Dead Pupae Research Articles

Moving towards fully circular insect production: A focus on insect-derived biowastes

Over the last decade, commercialization of insects for food and feed has been exponentially increasing. Insect protein is emerging as a sustainable livestock feed and human food alternative due to its low land and carbon footprint. The principles of insect industry are deeply embedded in the core values of sustainability and circular economy. Black soldier fly (BSF) is the crown jewel of insect industry and is one of the most commercially farmed insects. However, this steadfast growth is accompanied by generation of insect based biowaste such as dead flies and pupae exuviae. This will be a major waste fraction from this industry. This study discusses the valorization potential of this waste into chitin (which finds application in cosmetics, bioplastics, and pesticides, among other industries), biogas, fertilizer, and biochar. There is need to conduct more explorative research on value proposition of insect based biowaste to ensure that this industry can comply fully with circular economy and sustainability principles.

Population Dynamics of the Black Coffee Twig Borer <i>Xylosandrus compactus</i> (Eichhoff) in Robusta Coffee <i>Coffea canephora</i>

Population dynamics of Xylosandrus compactus (Eichhoff) lifestages in Robusta coffee were evaluated at the National Coffee Research Institute, Kituza, Uganda. Results revealed that its population and incidence varied with time, with brood size being highest in December and November 2020. Eggs were maximum in December 2020 and May 2021; larvae in November and December 2020 and May 2021; pupae in July 2021 and May 2021; and, adults in December 2020 and August 2021. Dead adults, live and total pupae decreased significantly (p≤0.05) with increasing temperature (R²=0.3435, 0.5598, 0.6017, respectively); eggs and dead pupae increased significantly (p≤0.05) with increasing rainfall (R²=0.5266, 0.6349, respectively); and, dead adults and live pupae decreased significantly (p≤0.05) with increasing relative humidity (R²=0.4383, 0.3635, respectively). This information will enable monitoring and predicting population buildup, and thus IPM decisions.

Commercial Culture of Cordyceps militaris from Waste Products of Sericulture in India

Cordyceps militaris, an entomopathogenic fungi belonging to Ascomycota group are currently in the limelight for its synthesis of Cordycepin, – an anti-cancer component. The host range of Cordyceps is extremely broad, with predominance on the orders Lepidoptera, Coleoptera, and Hymenoptera. Although this fungus is extremely rare in nature, its artificial culture is becoming more and more popular on the global market. However, the commercial culture of this fungus has been hampered by the difficulty in getting seeding material and the complex developmental technique. For ages, the silkworm (Order: Lepidoptera) has played a significant economic role in the food and silk industries of Asian nations. The waste product of the silkworm rearing process is the dead silkworm pupae, which are generated in large quantities after stifling of the cocoons for the purpose of producing raw silk. Waste from Sericulture in India has the potential to be used as a promising culture media for the growth of the Cordyceps-related sector, helping the silk farmers in their quest for future financial gain and the social advancement of the tribal society.

Evaluation of the efficiency of entomopathogenic nematodes exposed to different temperatures of vinasse in the control of Stomoxys calcitrans (Linnaeus, 1758) (Diptera: Muscidae).

The sugarcane industry generates byproducts that contribute to the proliferation of Stomoxys calcitrans. An analysis was carried out to verify the efficacy of Heterorhabditis bacteriophora HP88 and H. baujardi LPP7 at different vinasse temperatures to control S. calcitrans larvae. Ten fly larvae were deposited in plastic containers containing four mL of 50% vinasse. Each treatment consisted of 300 EPN/larvae of H. bacteriophora added to the containers and heated at temperatures of 25, 28, 31, 34, 37 and 40 °C. The same treatments were performed using H. baujardi. The treatments were carried out in a BOD incubator at 25 ± 1 °C and 70 ± 10% RH, and each treatment was replicated six times. The treated groups, controls and temperatures showed no statistical differences in terms of larval mortality rate (P=0.8573), percentage of dead pupae (P=0.1782) and adult emergence (P=0.4386). Larval mortality rates of 30% and 14.17% were achieved with H. bacteriophora and H. baujardi, respectively, while the control groups presented 3.89% with H. bacteriophora and 8.61% with H. baujardi. From the standpoint of temperatures, significant differences were found only at 37 and 40 °C for H. baujardi. The highest pupal mortality achieved with H. bacteriophora was 34.17% at 31 °C, while that reached with H. baujardi at 37 °C was 40%. The groups containing H. bacteriophora caused lower adult emergence rates at temperatures of 25, 28, 31 and 34 °C, while H. baujardi caused its lowest emergence rates at 37 and 40 °C. It is concluded that infection occurs in the immature stages of S. calcitrans by EPN when added to 50% vinasse solution at different temperatures and that nematodes caused negative effects on the emergence of fly larvae at varying temperatures.

Virulence of entomopathogenic bacteria Serratia marcescens against the red palm weevil, Rhynchophorus ferrugineus (Olivier).

The red palm weevil (RPW), Rhynchophorus ferrugineus (Olivier), is an important quarantine pest, which has caused serious economic losses in various palm species, such as coconut, oil palm and date palm. Finding effective biocontrol resources is important for the control of this pest and the protection of palm crops. A pathogenic strain HJ-01 was isolated from infected and dead pupa of Tenebrio molitor using tissue separation method. The HJ-01 strain was streak cultured and purified, and its morphological, physiological, biochemical characteristics, and 16S rDNA homology were identified after conducting a pathogenicity test on RPW larvae. Strain HJ-01 exhibited remarkable pathogenicity against RPW larvae. Under the concentration of HJ-01 suspension was 1.0 × 108 cfu/mL, the mortality rate of RPW reached 82.22%, and the half-lethal time (LT50) was 4.72 days. RPW larvae infected with strain HJ-01 showed reduced movement, decreased appetite, and eventual death. As the treatment progresses, the larvae's bodies turned red, became soft, and started to rot, resulting in the discharge of liquid. HJ-01 demonstrated the ability to produce scarlet pigment after 24 h of culture on a basic medium. Colonies of HJ-01 appeared convex, bright red, moist, and viscous, opaque in the center, irregular at the edges, and emitted an unpleasant odor. Under microscopic observation, the cells of HJ-01 appeared as short rod-shaped and flagellate, with a size ranging from (1.2-1.8) μm × (1.0-1.2) μm. Genomic DNA extraction was performed on the strain, and the 16S rDNA sequence was amplified, yielding a sequence length of 1445 bp. The sequence of strain HJ-01 displayed a 99.72% similarity to that of Serratia marcescens. Phylogenetic tree analysis further confirmed that strain HJ-01 belonged to S. marcescens. Therefore, the strain HJ-01 has a very good lethal effect on RPW larvae, and it may be used as an effective bacterium for the control of RPW.

Isolation characterization and pathogenicity of Helicoverpa armigera single nucleopolyhedrovirus isolate from Türkiye

The cotton bollworm, Helicoverpa armigera (Hübner) (Lepidoptera: Noctuidae), is a major pest of agricultural crops, such as cotton, horticultural plants, a range of vegetable crops and forest trees. Many dead and live larvae and pupa samples of H. armigera, an extremely polyphagous pest, were collected from Adana in Türkiye. It was observed that cadaveric integuments were fragile, and their body tissues were also liquefied. Studies with phase-contrast microscopy revealed a very intense baculovirus infection in cadavers. Transmission electron microscopy exhibited that the new baculovirus had one nucleocapsid in an envelope in the occlusion bodies. Therefore, the isolate was named Helicoverpa armigera single nucleopolyhedrovirus-D (HearSNPV-D). The phylogenetic analysis according to the polyhedrin and late expression factor-8 genes appeared that the new isolate was in close relationship with HearSNPV China and Türkiye isolate. The new isolate was tested on six different insects including its own host Helicoverpa armigera, Hyphantria cunea, Malacosoma neustria, Lymantria dispar, Thaumetopea pityocampa and Spodoptera exigua larvae. Bioassay studies showed that HearSNPV-D was virulent to H. armigera and had a narrow host range. The LC50 value was determined as 0.7 × 105 and 1.9 × 107 OBs/ml for H. armigera and S. exigua, respectively. Non-significant mortality was observed in non-host species by HearSNPV-D, which may reveal the highly specific nature of HearSNPV-D. Therefore, HearSNPV-D can be used as a specific, environmentally friendly control agent for H. armigera.

Deleterious Effects of Cymbopogon nardus (L.) Essential Oil on Life Cycle and Midgut of the Natural Predator Ceraeochrysa claveri (Navás, 1911) (Neuroptera: Chrysopidae).

Cymbopogon nardus (citronella) essential oil (EO) has been widely used in the cosmetic and food industry due to its repellent and fumigant properties. The aim of this study was to evaluate its effects on the life cycle and midgut morphology of the natural predator Ceraeochrysa claveri. Larvae were fed on sugarcane borer eggs (Diatraea saccharalis) pretreated with citronella EO solutions (1-100 µg/mL in methanol, 5 s) or solvent and air-dried at room temperature for 30 min. Larval and pupal stage duration, the percentage of emergence of the insect, and malformed insects were recorded. One day after adults emerged from their cocoons, adult insects were used to obtain their midgut and analyzed using light microscopy. The chemical composition of C. nardus EO revealed that citronellal (25.3%), citronellol (17.9%), geraniol (11.6%), elemol (6.5%), δ-cadinone (3.6%), and germacrene D (3.4%) were the predominant compounds. Exposure to the EO produced a significant change in development duration for third instar and prepupa of the insect. The observed alterations in the lifecycle included prepupae with no cocoon formation, dead pupa inside the cocoon, and malformed adults. Several injuries in the midgut epithelium of exposed adults were registered, such as detachment of columnar cells leaving only swollen regenerative cells fixed on the basement membrane, and the formation of epithelial folds. In summary, these data suggest that C. nardus oil has adverse effects on the life cycle and midgut morphology of a beneficial predator.

Taphonomic processes in a contemporary inhumation context. Megaselia scalaris (Diptera, Phoridae) larvae as a disturbing agent?

The study of cadaveric insect remains recovered in inhumation contexts allows drawing inferences about the circumstances surrounding death, about mortuary practices, and about the taphonomic history of human corpses. In this study the presence of the fly Megaselia scalaris associated with an infant skeleton buried in a contemporary cemetery is analyzed. The finding of the isolated mandibular central incisors, along with a large number of dead pupae and puparia within their alveolar cavities, prompted the analysis of the role of this species in the loss of skeletal integrity. In the present contribution, a monoespecific post-inhumation colonization by M. scalaris is identified, being for the first time proposed as a disturbing agent actively involved in the disarticulation of dental elements, produced by the feeding of necrophagous larvae. An integration of knowledge drawn from bioarchaeology and forensic entomology provides a significant contribution to the interpretation of taphonomic processes in funerary contexts.

Biochemical effects of lambdacyhalothrin on activities of some detoxifying enzymes of Anopheles gambiae life cycle stages

Recent decrease in global malaria burden was achieved through vector control interventions with pyrethroid insecticides. This study was carried out to determine the influence of lambdacyhalothrin on the physiology and activities of some detoxifying enzymes and to establish the systemic effects on Anopheles gambiae. The life cycle stages of the vector were exposed to six different concentrations of lambdacyhalothrin, in an insectary. After the toxicity tests, 325 each, of the dead eggs, larvae and pupae, and 175 of the dead adults from the toxicity test, were carefully selected and further used for enzyme study. Fifty (50) individuals were used for experimental study and 25 as control, for each of egg, larvae and pupae; 25 were used for experimental study and 25 as control for the adult. Each sample was homogenized in 10ml 0.1M phosphate buffer of pH 7.4, filtered and the filtrate used for enzymes study. Determination of the enzymes: aspartate aminotransferase (AST), alanine aminotransferase (ALT) and alkaline phosphatase (ALP) was done using standard biochemical methods. The results showed that 97% mortality of the life cycle stages was achieved following exposure to six concentrations of lambdacyhalothrin. Some concentrations (1 and 05µg/l) induced stimulatory effect on the enzyme activities while others (15 and 25µg/l) elicited inhibitory effect and some (10µg/l and 20µg/l) had no significant effect (p>0.05) on the enzyme activities. Alkaline phosphatase (ALP) was the most active in all the life cycle stages. Nevertheless, in older stages (pupae and adults), AST and ALT activities were significantly (p<0.05) elevated. This suggests that lambdacyhalothrin is promising in providing effective mosquito control. The results also suggest that the enzymes play a part in detoxification of lambdacyhalothrin and hence could be correlated with the pyrethroid tolerance status of A. gambiae.

Sublethal effects of oregano essential oil and its major compound carvacrol on biological parameters of Aedes albopictus (Diptera: Culicidae)

Mosquito management programs rely basically on the use of conventional synthetic larvicides. However, frequent applications and misuse of some synthetic insecticides have led to problems related to mosquito resistance development, harmful effects on human health and unacceptable environmental effects on non-target organisms. Recently, a growing number of phytochemicals has been tested as more eco-friendly larvicides against various mosquito species, exerting high efficacy with multiple modes of action. In the laboratory, we investigated for the first time the sublethal effects of oregano oil and its major compound carvacrol, against Aedes albopictus (Asian tiger mosquito), a mosquito of great medical importance. We determined the effects of short term (24h) exposure of 3rd- 4th larvae to LC50 concentrations on survival and development of survived larvae until adulthood, as well as on fecundity, fertility, longevity and wing length of emerged adults. Only half of 24h survived larvae from oregano oil and carvacrol treatment finally reached adulthood. Abnormal shapes of dead larvae and pupae, and failed adult emergence were also observed, indicating a potential growth inhibitory activity of the tested materials. No particular effects from exposure to larvicidal LC50 concentrations were recorded on life cycle parameters of successfully emerged adults. These findings suggest the tested oregano oil and carvacrol as sufficiently effective larvicides against Ae. albopictus at lower than the acutely toxic concentrations, promoting a more eco-friendly and less costly profile for these biopesticides.

Selective aspects of the epizootiology of Parathelohania iranica (Microsporidia: Amblyosporidae)

Parathelohania is a genus of microsporidia that preferentially attacks Anopheline mosquitoes. This study explored some selective aspects of the epizootiology of Parathelohania iranica (Microsporidia: Amblyosporidae) in its malaria mosquito host Anopheles superpictus s.l. (Diptera: Culicidae). For this study, Sar-rok Village, a place adjacent to the type locality of the parasite, located at the central western part of Iran was visited twice a month to collect host larvae from mid-summer to mid-autumn of 2017–2021. Patent infections were detected by the whitish discoloration of the involved segments. Superficially uninfected larvae were reared up to 26 days in the insectary to elucidate hidden infections. Molecular investigation and laboratory trials were conducted to evaluate the possibility of secondary infections in subsequent days. Morphological characters were used to determine the sex of larvae and adults. Data were entered in SPSS 23.0 and analyzed with relevant statistical tests as needed. In total, 584 P. iranica infected larvae of An. superpictus s.l. were collected in the study years at day zero (D0). Extended observations in the insectary revealed that 849 larvae (84.2 %), 22 dead pupae (2.2 %), and 137 emerged adults (13.6 %) were also infected. In the first two years of the study, the mean infection rate for D0 and D0 + D1-D26 infections was 6.25 % and 15.6 %, respectively. Exposure experiments indicated that subsequent infections in larvae (D1-D26) were not affected by a possible source in the accompanying field water. Patent (D0) infections were seasonal and had about a month delay compared to the general population of larvae. Concealed infections of larvae (D1-D26) were significantly more frequent in late mosquito season (P < 0.01). It is proposed that the gradual decrease of ambient temperature and the shortening of day length postpones the growth and development of P. iranica in the affected larvae. Both sexes of larvae were involved and none of them survived beyond a couple of days. The frequency of infections in adult males (5.8 %) were significantly more than females (4 %) (P = 0.02). The infections of larvae were more common in the late mosquito season, and the infections of adults were more frequent in the early mosquito season. This suggests the relative importance of vertical and horizontal routes of transmission in early and late mosquito seasons, respectively. However, age-specific data revealed that only 26 % of hidden infections of larvae (D1-D26) were stemmed from I to II age group. This implies that the vertical route may be less efficient than the horizontal route in the transmission of P. iranica to the mosquito host. These inferences should be verified with further field and laboratory investigations.

Larvicidal and pupicidal potential of Alchornea cordifolia (Schum. &amp; thonn.) leaf extract against the malaria vector Anopheles gambiae (Diptera: culicidae)

The Anopheles mosquito is one of the major medically important pests in Ghana. This research was to evaluate the larvicidal and pupicidal activities of Alchornea cordifolia leaf extract against Anopheles gambiae mosquitoes in the laboratory. Twenty 3rd/4th larval instar as well as two days old pupae were introduced into the treatments and control and replicated four times. The number of dead larvae and pupae were counted and recorded after 24 hours. Larvae and pupae mortality occurred in a dosage-dependent manner. There were significant differences in toxicity level of the leaf extracts on An. gambiae larvae and pupae at concentrations after 24 hours of exposure. LC50 and LC90 recorded after probit analysis for the larvae was 52.19mg/L and 180.10mg/L respectively and that for the pupae was 189.97mg/L and 857.00mg/L respectively. A. cordifolia leaf extract could serve as a potential larvicidal and pupicidal agent.

A Four Stage Image Processing Algorithm for Detecting and Counting of Bagworm, Metisa plana Walker (Lepidoptera: Psychidae)

The bagworm is a vicious leaf eating insect pest that threatens the oil palm plantations in Malaysia. The economic impact from defoliation of approximately 10% to 13% due to bagworm attack might cause about 33% to 40% yield loss over 2 years. Due to this, monitoring and detecting of bagworm populations in oil palm plantations is required as the preliminary steps to ensure proper planning of control actions in these areas. Hence, the development of an image processing algorithm for detection and counting of Metisa plana Walker, a species of Malaysia’s local bagworm, using image segmentation has been researched and completed. The color and shape features from the segmented images for real time object detection showed an average detection accuracy of 40% and 34%, at 30 cm and 50 cm camera distance, respectively. After some improvements on training dataset and marking detected bagworm with bounding box, a deep learning algorithm with Faster Regional Convolutional Neural Network (Faster R-CNN) algorithm was applied leading to the percentage of the detection accuracy increased up to 100% at a camera distance of 30 cm in close conditions. The proposed solution is also designed to distinguish between the living and dead larvae of the bagworms using motion detection which resulted in approximately 73–100% accuracy at a camera distance of 30 cm in the close conditions. Through false color analysis, distinct differences in the pixel count based on the slope was observed for dead and live pupae at 630 nm and 940 nm, with the slopes recorded at 0.38 and 0.28, respectively. The higher pixel count and slope correlated with the dead pupae while the lower pixel count and slope, represented the living pupae.

Oto-BaCTM: An Automated Artificial Intelligence (AI) Detector and Counter for Bagworm (Lepidoptera: Psychidae) Census

The bagworm species of Metisa plana, is one of the major species of leaf-eating insect pest that attack oil palm in Peninsular Malaysia. Without any treatment, this situation may cause 43% yield loss from a moderate attack. In 2020, the economic loss due to bagworm attacks was recorded at around RM 180 million. Based on this scenario, it is necessary to closely monitor the bagworm outbreak at infested areas. Accuracy and precise data collection is debatable, due to human errors. . Hence, the objective of this study is to design and develop a specific machine vision that incorporates an image processing algorithm according to its functional modes. In this regard, a device, the Automated Bagworm Counter or Oto-BaCTM is the first in the world to be developed with an embedded software that is based on the use of a graphic processing unit computation and a TensorFlow/Teano library setup for the trained dataset. The technology is based on the developed deep learning with Faster Regions with Convolutional Neural Networks technique towards real time object detection. The Oto-BaCTM uses an ordinary camera. By using self-developed deep learning algorithms, a motion-tracking and false colour analysis were applied to detect and count number of living and dead larvae and pupae population per frond, respectively, corresponding to three major groups or sizes classification. Initially, in the first trial, the Oto-BaCTM has resulted in low percentages of detection accuracy for the living and dead G1 larvae (47.0% &amp; 71.7%), G2 larvae (39.1 &amp; 50.0%) and G3 pupae (30.1% &amp; 20.9%). After some improvements on the training dataset, the percentages increased in the next field trial, with amounts of 40.5% and 7.0% for the living and dead G1 larvae, 40.1% and 29.2% for the living and dead G2 larvae and 47.7% and 54.6% for the living and dead pupae. The development of the ground-based device is the pioneer in the oil palm industry, in which it reduces human errors when conducting census while promoting precision agriculture practice.

An investigation of the efficacy of hygienic behavior of various honey bee (Apis mellifera) races toward Varroa destructor (Acari: Varroidae) mite infestation

Hygienic behavior in honey bees reflects the social immunity against parasites and diseases and is considered one of the main factors of genetic resistance of the bee breeding program. Hygienic behavior refers to the uncapping and removal of diseased and dead larvae and pupae from sealed brood cells by the worker bees. Here, the hygienic behavior of Apis mellifera races was investigated in response to pin-killed assay and artificial Varroa mite-infested brood cells. Moreover, the reproduction behavior of Varroa mites was determined in various sizes of honey bee race comb cells. The results revealed that the percentage of uncapping and removal of dead broods were significantly higher in the Italian as compared to the Carniolan bee colonies (p < 0.05). Similarly, a significant difference was present in response to artificially infested brood cells with Varroa mites in Italian and Carniolan colonies over the day of inspection (p < 0.05). Overall, the width of cells of the two types of combs was significantly different. The smaller width of cells size combs reduces the Varroa mite reproduction behavior compared to larger cell size combs. More infestation of Varroa mite occurred in drone brood cells as compared to worker brood cells in both old and new comb types. This study contributed to understand the hygienic behavior of A. mellifera races in preparation for selecting and developing hygienic lines of bees given the important contribution of hygienic behavior to honey bee health.

Entomopathogenic nematodes as potential biocontrol agents against Bactrocera oleae (Diptera: Tephritidae)

ABSTRACT The olive fruit fly Bactrocera oleae is one of the most serious and economically damaging insects worldwide, affecting the quality and quantity of both olive oil and table olives. Third instar larvae and pupae of several Tephritidae flies were reported to be susceptible to entomopathogenic nematodes (EPNs), but few studies have been carried out on the olive fruit fly. Laboratory assays were conducted to evaluate the susceptibility of B. oleae larvae and pupae to two commercial EPN species, Steinernema feltiae and Heterorhabditis bacteriophora and two indigenous Italian strains of H. bacteriophora and Steinernema carpocapsae. Moreover, an olive assay in the soil was performed to evaluate the capability of EPN strains to enter inside the olive fruits and interact with B. oleae during the pupal stage or the emergence of adults in the winter diapause. The susceptibility assays with B. oleae were performed in well plates, filled with sterile soil (n = 30 for each EPN strain and insect stage). Adult emergence and mortality were recorded daily for 15 days. Dead pupae and adults were dissected to assess nematode infection. The most noteworthy result was obtained with S. feltiae which was able to infect more than 80% of larvae and it killed the pupae inside olive fruits and the adults during their emergence with the same efficacy. Since this Tephritidae fly spends several months in the soil, the use of EPNs, in particular, S. feltiae may represent a promising method to control this pest.

Unlucky spider flies (Diptera: Acroceridae) trapped in a tomb of mud: An Australian predatory wasp (Sphecidae) provisions its nest with parasitised spiders (Salticidae)

Acroceridae, known as spider flies, are exclusive endoparasitoids of spiders. This study reports the first host association for Ogcodes pygmaeus White, 1914 (Diptera: Acroceridae) after discovering dead acrocerids and their host spiders inside Sceliphron formosum Smith, 1856 (Hymenoptera: Sphecidae) nests in ACT, Australia. From a total of 650 sampled wasp nests, 14 were discovered with multiple spiders parasitised by species of Ogcodes Latreille, 1796. Two species of jumping spiders in the genus Servaea Simon, 1887 (Araneae: Salticidae), including an undescribed species, were identified as hosts of O. pygmaeus in this study. We hypothesise that the parasitised spiders were brought back to the nest as S. formosum prey items, and when acrocerid adults emerged they were trapped inside the sealed nests. Dead pupae were also found in the nests along with the dead adult acrocerids. To our knowledge, this entrapment of spider parasites inside S. formosum nests has not been documented before, and this study represents a new method for obtaining acrocerid fly host records.

Etiology, symptoms and prevention of chalkbrood disease: a literature review

ABSTRACT The fungus Ascosphaera apis, responsible for causing the chalkbrood disease of honey bees, is widely present in temperate regions of the northern hemisphere, but has also spread to other regions of the world such as Brazil. Although it is not usually lethal for the colony, it can reduce its population, hampering its development. This study is a review on the disease that presents a broad overview of its development, identification methods as well as ways to control it. Research shows that chalkbrood is associated with several factors and is most frequently found in colonies of Apis bees during the spring, when there is excess humidity and sudden temperature changes in the hive. Other factors such as viral or bacterial infection, the presence of the ectoparasite Varroa destructor, pesticide poisoning and poor nutrition of nurse bees can also affect its incidence and severity. Field diagnosis is made based on the presence of hardened mummified brood in the pupal stage, of white or black color, in the cells and entrance. Affected cells show dead pupae covered with white mycelia, resembling cotton, or hardened, dry and brittle, resembling chalk pieces, which originated the name. To date, there are no efficient methods to reduce the damage caused by chalkbrood. Genetic selection of bees with higher hygienic behavior and disease resistance is recommended.

Multispectral imaging for quality control of laboratory‐reared Anastrepha fraterculus (Diptera: Tephritidae) pupae

AbstractThe sterile insect technique (SIT) has been widely used to suppress several fruit fly species. In southern Brazil, millions of sterile flies of the South American fruit fly, Anastrepha fraterculus Wiedemann (Dipetra: Tephritidae), will be produced in a mass‐rearing facility called MOSCASUL to suppress wild populations from commercial apple orchards. In spite of standard rearing conditions, the quality of pupal batches can be inconsistent due to various factors. The quantification of poor quality material (e.g. empty pupae, dead pupae or larvae) is necessary to track down rearing issues, and pupal samples must be taken randomly and evaluated individually. To speed up the inspection of pupal samples by replacing the manual testing with the mechanized one, this study assessed a multispectral imaging (MSI) system to distinguish the variations in quality of A. fraterculus pupae and to quantify the variations based on reflectance patterns. Image acquisition and analyses were performed by the VideometerLab4 system on 7‐d‐old pupae by using 19 wavelengths ranging from 375 to 970 nm. The image representing the near infrared wavelength of 880 nm clearly distinguished among high‐quality pupae and the other four classes (i.e. low‐quality pupae, empty pupae, dead pupae and larvae). The blind validation test indicated that the MSI system can classify the fruit fly pupae with high accuracy. Therefore, MSI‐based classification of A. fraterculus pupae can be used for future pupal quality assessments of fruit flies in mass‐rearing facilities.

VIRULENCE OF ENTOMOPATHOGENIC NEMATODE TO PUPAE AND ADULTS OF Drosophila suzukii IN LABORATORY

Drosophila suzukii is considered one of the most important pests of fruit farming. Due to its rapid expansion, control alternatives of this fly should be investigated. The use of entomopathogenic nematodes (EPNs) represents an important tool in the control. This study aimed to evaluate the virulence of EPNs isolates in pupae and the repercussion in adults of D. suzukii in laboratory. The experiment was conducted in a completely randomized design with five treatments and five replicates. Each plot consisted of a Petri dish lined with two sheets of filter paper. The isolates Heterorhabditis amazonensis IBCBn 24, Heterorhabditis indica IBCBn 05, Steinernema carpocapsae IBCBn 02 and Steinernema feltiae IBCBn 47 were inoculated into 2 mL at the concentration of 1,000 infective juveniles IJs/mL. The control treatment consisted of 2 mL distilled water. After inoculation, five pupae of D. suzukii were placed in the Petri dishes, which were then sealed and stored in a BOD climate chamber at 26 ± 1ºC, 70 ± 10% RH in the dark. Assessments were performed daily until the emergence of adults. Dead pupae and adults were dissected for the observation and quantification of IJs. The isolates, H. indica IBCBn 05, H. amazonensis IBCBn 24, S. carpocapsae IBCBn 02 and S. feltiae IBCBn 47, infected and made unviable 35.0, 16.0, 13.0 and 43.0% in pupae and 47.0, 80.0, 84.0 and 57.0 % in adults of D. suzukii. H. indica IBCBn 05 obtained the highest number of IJs produced in pupae and adults, 35.0 and 125.0.