Clitostethus Arcuatus Research Articles

Florida red scale, Chrysomphalus aonidum (Linnaeus, 1758) (Hemiptera: Diaspididae) in Morocco, infesting citrus orchards and an avocado tree

AbstractA study was conducted on citrus and avocado trees in north‐western Morocco between February 2023 and April 2024 to detect scale insects (Hemiptera: Coccomorpha) and their associated natural enemies. A total of 55 orchards in seven provinces were studied. The Florida red scale, Chrysomphalus aonidum (Linnaeus, 1758) (Diaspididae) was found on leaves at two sites: a moderate infestation in one citrus orchard and one specimen on an avocado tree. This work is the first record of the scale insect on avocado in Morocco, and the first morphological description of C. aonidum from the country, based on 100 adult females mounted on microscope slides. Chrysomphalus aonidum is not causing economic damage in citrus or avocado orchards in Morocco. Two ectoparasitoid wasps (Aphytis melinus DeBach and Aphytis sp.; Hymenoptera: Aphelinidae), and three predatory beetles (Rhyzobius lophanthae Blaisdell, Chilocorus bipustulatus Linnaeus, and Clitostethus arcuatus Rosso; Coleoptera: Coccinellidae), were found associated with C. aonidum on citrus leaves.

FIRST DATA ON ESTABLISHMENT AND POPULATION TREND OF THE NEOTROPICAL DELPHASTUS CATALINAE (HORN, 1895) (COLEOPTERA COCCINELLIDAE) IN ITALY

After the first record in 2018 in southern Italy and in Sicily, the Neotropical ladybird Delphastus catalinae (Horn, 1895) (Coleoptera: Coccinellidae, Sticholotidinae) has been rediscovered and monitored in Sicily. The population of this non-indegenous species was observed in an experimental citrus orchard with organic management in eastern Sicily. D. catalinae is the only Italian and Sicilian allochthonous ladybird species with Neotropical origin. It was abundant in the study area and active all year, especially in autumn-winter. Overall, a total of 971 specimens of D. catalinae were collected during the three years field surveys on twenty sampled trees. Over the years the population of D. catalinae increased, as increased the percentage of D. catalinae specimens on the total number of ladybirds collected. More studies will be needed for monitoring the spread of D. catalinae in Sicily and the effective interaction with other indigenous ladybird predators of Aleyrodidae like Clitostethus arcuatus (Rossi, 1794). Key Words: Ladybeetles; Delphastus catalinae; Delphastus pusillus; Clitostethus arcuatus; Italy; Biological invaders.

Düzce ili karayaprak lahanası bahçelerinde belirlenen yararlı, zararlı böcek türleri ve biyo-ekolojileri

Karayaprak lahanası (Brassica oleracea L. var. acephala) Karadeniz Bölgesi’nde yaygın olarak yetiştirilen en önemli kışlık sebzeler arasındadır. Karadeniz Bölgesi’nin batısında bulunan Düzce ili karayaprak lahanası bahçelerinde faydalı ve zararlı türleri belirlemek amacıyla 2016-2017 yıllarında sürvey çalışmaları yürütülmüştür. Çalışma sonucunda 4 takıma bağlı 7 familyadan 18 zararlı türü ve 4 takıma bağlı 4 familyadan 5 faydalı tür tespit edilmiştir. Karayaprak lahanası bahçelerinde Lahana beyazsineği, Aleyrodes proletella L. (Hemiptera: Aleyrodidae)’nın ana zararlı konumunda olduğu ve bu zararlının önemli olabilecek seviyelerde popülasyon oluşturduğu tespit edilmiştir. Bunun yanı sıra yaprak bitleri Brevicoryne brassicae L., Aphis craccivora Koch (Hemiptera: Aphididae)’nın da karayaprak lahanasında zarara yol açtığı belirlenmiştir. Bazı bahçelerde ise yaprak pireleri Phyllotreta cruciferae Goeze, P. atra Fabricius, P. variipennis Boieldieu, P. striolata Fabricius ve P. undulata Kutschera (Coleoptera: Chrysomelidae) ile Lahana kelebeği Pieris brassicae (L.) ve P. rapae (L.) (Lepidoptera: Pieridae)’nın da zaman zaman önemli zararlı türler olarak ortaya çıktığı saptanmıştır. Karayaprak lahanası bahçelerinde Encarsia tricolor Foerster (Hymenoptera: Aphelinidae) ve Clitostethus arcuatus Rossi (Coleoptera: Coccinellidae)’un ise en yaygın faydalı türler olduğu belirlenmiştir.

An annotated checklist of Coccinellidae (Insecta, Coleoptera) with eight new records from the Kingdom of Saudi Arabia.

The members of Coccinellidae are among the most important biological control agents being used throughout the world. The objective of this study was to provide the current scenario of this family in Saudi Arabia. Collection surveys of ladybird individuals were conducted throughout Saudi Arabia. A total of 5400 specimens of Coccinellidae were collected belonging to 51 species in 19 genera and seven tribes: Sticholotidini (2 genera / 10 species), Coccidulini (1/3), Scymnini (4/24), Diomini (1/1), Hyperaspidini (1/3), Chilocorini (3/8), Noviini (1/3), Coccinellini (8/11), Epilachnini (2/2). One genus, Clitostethus, and eight species and subspecies, Cheilomenes lunata lunata (Fabricius, 1775), Clitostethus arcuatus (Rossi, 1794), Nephus ornatulus Korschefsky, 1931, N. nigricans (Weise, 1879), Pharoscymnus fleischeri (Weise, 1883), Novius yemenensis Raimundo & Fürsch, 2006, Scymnus (Scymnus) scapuliferus Mulsant, 1850, and Stethorus endrodyi Fürsch, 1970, are reported as new records to Saudi Arabia. Two endemic species, Scymnus agrumi and S. arabicus, were recorded. This study also describes the geographical distribution for each species and the diagnostic characters for new records.

Düzce ilinde karayaprak lahanasında (Brassica oleracea L. var. acephala) zararlı Aleyrodes proletella L. (Hemiptera: Aleyrodidae)’nın yayılışı, konukçuları ve doğal düşmanları

This study was carried out on distribution, density, host plant, and natural enemies affecting its population fluctuation of Aleyrodes proletella L. (Hemiptera: Aleyrodidae) on collard during the years of 2016-2017 in Düzce province in Western Black Sea Region. Aleyrodes proletella was widespread in all districts of Düzce province and the infestation rate was 84.3%. The highest infestation rates were determined in Akçakoca (97.8%), Yığılca (93.3%), Gümüşova (88.9%), Kaynaşlı (84.4%), Cumayeri (82.2%), Gölyaka (80%), Çilimli (75.6%) and Central (75%) districts, respectively. Hosts of A. proletella except collard was determined that white cabbage (Brassica oleracea L. var. capitata) and Lapsana communis L. subsp. intermedia (Bieb.) Hayek plant which is called as common nippleworth belonging to the Asteraceae (Capparales) family. Parasitoid of A. proletella was detected as Encarsia tricolor Förster (Hymenoptera: Aphelinidae), and predators of A. proletella were found as Clitostethus arcuatus Rossi (Coleoptera: Coccinellidae) and Chrysoperla carnea Stephens (Neuroptera: Chrysopidae).

On a Finding of the Southern Palaearctic Ladybird Clitostethus arcuatus (Rossi) (Coleo ptera, Coccinell idae) in Moscow Province

In the Balashikha Urban District of Moscow Province, a ladybird, Clitostethus arcuatus (Rossi), predator of the cabbage whitefly (= celandine whitefly) Aleyrodes proletella (L.), was collected in May 2019 on celandine, Chelidonium majus L., in a coniferous forest. This southern Palaearctic ladybird had been previously known from natural habitats in Russia only in the Northwestern Caucasus.

BIODIVERSITY AND DIET OF COCCINELLIDAE ON CITRUS IN METIDJA (ALGERIA)

Biological control is a viable alternative to the use of chemical pesticides that are harmful to the environment. From this perspective, this work aims to make an inventory of Coccinellidae and to classify them according to their diet. Sampling by yellow sticky plates is carried out each week from 23 April to 24 July 2014 at the Eastern Metidja very important citrus region in Algeria. A total of 16 ladybug species are sampled in four citrus species, orange, lemon, clementine and pomelo. It is the Coccidiphagous that are the richest with a total of 7 species, followed by the aphidophagous with 5 species and mycophagous with the two species. Finally found the aleurodiphagous and acariphagous, with a single species for each group. With regard to relative abundance, a total of 467 individuals coccinellidae were captured, of which the species Clitostethus arcuatus (ladybug aleurodiphagous) alone counted 285 individuals, that is 61.29%.

Natural enemies associated with the cabbage whitefly Aleyrodes proletella in Germany

Aleyrodes proletella Linnaeus (Hemiptera: Aleyrodidae) causes severe economic damage on cabbage crops especially in organic vegetable production. Cabbage producers lack efficient and sustainable control measures against this major pest. Knowledge on the regional diversity of its natural enemies is required for the development of biological and integrated strategies to regulate A. proletella populations. Therefore, a 3-year survey of the natural enemies of A. proletella was conducted at five locations across Germany. For this purpose, parasitoids and predators were sampled from organic Brussels sprouts fields that were highly infested with A. proletella. Encarsia tricolor Forster (Hymenoptera: Aphelinidae) was the dominant parasitoid species and comprised 99.5% of all parasitoids encountered. Other parasitoids were Encarsia inaron Walker (Hymenoptera: Aphelinidae) and Euderomphale chelidonii Erdos (Hymenoptera: Eulophidae). Most sampled predators were hoverfly larvae (49.6%) followed by spiders (33.8%), ladybeetles (14.2%), predatory bugs (1.6%) and lacewing larvae (0.8%). Harmonia (Coleoptera: Coccinellidae), Sphaerophoria, Episyrphus (Diptera: Syrphidae) and Tetragnatha (Araneae: Tetragnathidae) were the most abundant genera of predators. The only whitefly specialist among the predators was Clitostethus arcuatus Rossi (Coleoptera: Coccinellidae). A detailed list of identified natural enemies is provided, and their relevance in naturally regulating A. proletella populations discussed and possible implementations in pest management strategies are proposed.

New data on the distribution of ladybird beetles (Coleoptera: Coccinellidae) in the eastern part of the Baltic Coast region in Poland

New data on the occurrence of ladybird beetles in the eastern part of the Baltic Coast of Poland are presented. Studies were carried out between 2012 and 2017 along the Baltic coast from Krynica Morska to Białogóra. We found 44 species of Coccinellidae. Ten of the recorded species (Clitostethus arcuatus, Scymnus haemorrhoidalis, S. limbatus, S. abietis, S. auritus, S. rubromaculatus, Stethorus pusillus, Hyperaspis concolor, H. reppensis, Platynaspis luteorubra) are reported for the first time from the investigated area. Two of them, C. arcuatus and S. pusillus, are new for the whole Baltic Coast region of Poland. The recorded contribution of the invasive Harmonia axyridis to all ladybird individuals was relatively low (12.7%).

Winter and early spring assemblages of ladybird beetles (Coleoptera: Coccinellidae) in two forest habitats in suburban area of Warsaw, central Poland

In March and April of 2014 and 2015, overwintering and post-overwintering assemblages of ladybird beetles were investigated in deciduous (Tilio-Carpinetum) and mixed forest (Querco roboris-Pinetum) patches in a forest complex on the north-western periphery of Warsaw. March samples were collected by sifting forest litter with an entomological sieve, while in April, ladybirds were collected from the vegetation using sweeping net and beating sheet. In both years, mean densities of ladybirds found in March in the two forest types were low, not exceeding 2 individuals/m2. Seven ladybird species were found overwintering in the litter of the deciduous forest and four in that of the mixed forest. Propylea quatuordecimpunctata was the most abundant in both habitats in 2014, while in 2015 in the litter of the deciduous forest Vibidia duodecimguttata predominated. In April, 15 species were recorded in the deciduous forest and 7 in the mixed forest. Scymnus ferrugatus predominated in the former plant community and P. quatuordecimpunctata and Coccinella septempunctata in the latter. Several of the recorded species, such as Clitostethus arcuatus, Scymnus femoralis and S. abietis, have rarely been reported from Poland.

WHITEFLIES (HEMIPTERA : ALEYRODIDAE) INFESTED ORCHARDS AND THEIR NATURAL ENEMIES IN EGYPT

Whiteflies (Aleyrodidiae: Hemiptera) are the most economic pests infested orchards trees in Egypt. The present work dealt with the whiteflies infested orchards and their natural enemies in Egypt as well as world literature of host plants, distribution and natural enemies of these pests. The results indicated that nine species of whiteflies were recorded infested orchards trees in Egypt as well as 8 new natural enemies associated with these pests. Also constructed key of the nine species of whiteflies was provided. The host plants, distribution and natural enemies were reported. The seasonal abundance of the black citrus whitefly ,Acaudaleyrodes rachipora (Singh) was studied for two successive years from 2010- 2011 on citrus trees in Qalyubyia .The obtained results showed that, the insect population reached maximum during April in first and second years, respectively. Numbers of Encarsia acaudaleyrodis reached maximum during April during the first and second years .There is no predators collected from this location. The seasonal abundance of sycamore whitefly, Aleurolobus marlatti (Quaintance) was studied for two successive years from 2010-2011 on sycamore trees .The obtained results showed that, the insect population reached maximum during May in the first and second years, respectively. Numbers by Encarsia elegans reached maximum during May during the first and the second years . The predator Orius lavigatus reached maximum during May of the first and the second years .The seasonal abundance of the olive whitefly, Aleurolobus olivinus (Silvestri) was studied for two successive years from 2010-2011 on olive trees in El-Arish .The obtained results showed that, the insect population reached maximum during June in first year and May in the second one. Numbers of Encarsia olivina reached maximum during June of the first year and May during the second one. There is no predators collected from this location. The seasonal abundance of the pomegranate whitefly, Siphoninus phillyreae (Haliday) was studied for two successive years from 2010-2011 on pomegranate trees in Assuit .The obtained results showed that, the insect population reached maximum during August in both first and second year. Numbers of Encarsia inaron reached maximum during August of the first year and September during second years .There is no predators collected from this location. Also the same study conducted during two successive years from 2010-2011 on pomegranate trees in Daqahlyia .The obtained results showed that, the insect population reached maximum during August in first and second years. Numbers of the predator Clitostethus arcuatus reached maximum during August of the first year and July during second years .There is no parasitoids collected from this location. During the present work the whitefly Bemisia afer (Priesner & Hosny) on citrus during 2010-2011 was very rarely in Behira and 47 and 62 individuals only collected during the first ad second years, respectively The numbers of the parasitoid, E. mundus was also very rarely,4 individuals only collected during the period of study.During the present work the whitefly Aleuroclava jasmini , the whitefly Bemisia afer(Priesner & Hosny) and the cotton whitefly, Bemisia tabaci and their parasitoids were very rarely on citrus during 2010-2011 in Qalyubiya. During the present work the citrus whitefly , Dialeurodes citri (Ashmead) and Japanese bayberry whitefly,Parabemisia myricae (Kuwana) on citrus during 2010-2011 was not recorded and collected during the period of study.

Life table attributes of Clitostethus arcuatus (Coleoptera: Coccinellidae) feeding on Trialeurodes vaporariorum and Siphoninus phillyreae (Hemiptera: Aleyrodidae)

The ladybird beetle Clitostethus arcuatus Rossi (Coleoptera: Coccinellidae) is one of the most effective predators of the greenhouse whitefly, Trialeurodes vaporariorum Westwood, and the ash whitefly, Siphoninus phillyreae Haliday (Hem: Aleyrodidae). Two stock cultures of C. arcuatus were established under controlled conditions (25±2°C, 65±5%RH and L–D:16–8), one using T. vaporariorum and one using S. phillyreae as prey. Newly laid C. arcuatus eggs from each culture were evaluated for immature survival. Thirty pairs of C. arcuatus (24h-old) were selected for studying the reproductive life history of C. arcuatus on the two hosts. Results showed that the period between oviposition and hatch did not show significant difference on different prey. Duration of different instars stages of C. arcuatus differed significantly, except second instars, which was 4days for both diets. Pupal period differed significantly between the two prey types. Egg hatch was 95% and 91.7% for adults fed on T. vaporariorum and S. phillyreae, respectively. There was a significant difference among some treatments for gross fecundity rate and net reproductive rate (R0), indicating that prey had a significant impact on the biological activities of C. arcuatus. The intrinsic rate (rm) and finite rate of increase (λ) were 0.063 and 0.078, respectively, for T. vaporariorum, and 1.0026 and, 1.08, respectively, for S. phillyreae.

Predation efficiency of Clitostethus arcuatus (Rossi) (Coleoptera: Coccinellidae) on different stages of jasmine whitefly Aleuroclava jasmini Takahashi on citrus leaves

The study was conducted in laboratory at 27 ±2ْ C temperature and 60-70% relative humidity to evaluate the predation efficiency for the predator Clitostethus arcuatus on different stages of Aleuroclava jasmini on citrus leaves. The results showed that predator larvae feed on all immature stages of jasmine whitefly and the predation percentage was increased due to an increase in larval age. The average number of preys per predator larva were 1095.6 eggs, 1124.9 crawlers, 803.1 2nd nymphal instar, 360.8 3rd nymphal instar and 122.1 4th nymphal instar, while the duration of development of larvae were 11.3, 14.1, 14.2, 14.3 and 15.1 days when they feed on eggs, crawlers, 2nd nymphal instar, 3rd nymphal instar and 4th nymphal instar, respectively. The predator adults began to search and feed on preys after about one hour of emergence from pupa stage and prey all stages of jasmine whitefly. The average number of preys consumed by each predator adult during ten days were 1599.3, 1137.1, 644.5, 282.0, 156.3 and 120.2 of eggs, crawlers, 2nd nymphal instar, 3rd nymphal instar , 4th nymphal instar and adult, respectively.

The effect of diet on longevity, fecundity, and the sex ratio of Clitostethus arcuatus (Rossi) (Coleoptera: Coccinellidae)

Clitostethus arcuatus is a major, cosmopolitan predator of some Aleyrodidae. Field collected adult beetles were reared in the laboratory on different diets: Siphoninus phillyreae eggs, Trialeurodes vaporariorum eggs, Sitotroga cerealella eggs, or an artificial diet consisting of honey, yeast, and pollen. All experiments were conducted at 25 ± 2 °C, 65 ± 5% RH and a photoperiod of 16:8 (L:D) h. Female and male C. arcuatus consumed a mean (± SE) of 61 ± 0.6 and 27 ± 0.9 T. vaporariorum eggs d − 1 , respectively, and a mean of 56 ± 2.2 and 29 ± 1.1 S. phillyreae eggs d − 1 , respectively. Significant differences were noted between sexes and between hosts consumed by female C. arcuatus. No feeding occurred on S. cerealella eggs. Although there was a significant difference between rates of oviposition due to diet, fertility rates on different diets did not show significant differences. The sex ratio of C. arcuatus (female:male) was 51.4:48.6, 55.2:44.8, and 54.6:45:4 when adults fed on T. vaporariorum, S. phillyreae, and artificial diet, respectively. These differences were not significantly different. Average longevity (± SE) was 66.4 ± 2.6, 54.9 ± 2.5; 77.3 ± 6.9, 67.5 ± 7.2; and 86.4 ± 4.5 70.3 ± 3.6 days for female and male C. arctuatus, respectively, on T. vaporariorum, S. phillyreae and artificial diet, respectively, with significant differences between sexes and diets. Although developmental duration on T. vaporariorum was longer than ash whitefly, this difference was not significant (mean 27.68 ± 0.31 and 25.09 ± 0.21 days for predators reared on T. vaporariorum and S. phillyreae, respectively). Given its longevity and fecundity on T. vaporariorum, C. arcuatus may be a good choice for mass release on glasshouse crops infected by greenhouse whitefly.

Ladybirds associated with pistachio trees in part of Kerman province, Iran (Coleoptera: Coccinellidae)

The majority members of the family Coccinellidae are predators, so they have received considerable research attention because of their potential to act as biocontrol agents. The coccinellids complex of pistachio trees was monitored at both cultivated and wild pistachio plantations in Shahr-e Babak (Kerman, Iran) during 2009 - 2010. Sampling was carried out randomly in the cultivated pistachio plantations at elevations between 1590 - 1864 m and the wild pistachio growing areas at elevations between 2103-2364 m, using a white beating tray. Totally, 25 species belonging to 14 genera from six tribes and four subfamilies were collected. 21 and 15 species were identified on cultivated and wild pistachio plantations respectively, among which eight new species for Kerman province were recorded. Chilocorus bipustulatus, Exochomus quadripustulatus, Parexochomus nigripennis , Hyperaspis polita, Hyperaspis sp, Menochilus sexmaculatus, Nephus (Nephus) quadrimaculatus, Nephus (Sidis) elbursi, Scymnus (Scymnus) flavicollis, Pharoscymnus setulosus, were found in few experimental sites on planted pistachio trees only. In addition Exochomus octosignatus, Clitostethus arcuatus, Parexochomus melanocephalus and Scymnus (Pullus) auritus were only collected from wild pistachio trees.

Augmentation and evaluation of a parasitoid, Encarsia inaron, and a predator, Clitostethus arcuatus, for biological control of the pomegranate whitefly, Siphoninus phillyreae

The aim of this study was to evaluate the biological control potential of Encarsia inaron (Walker) (Hymenoptera: Aphelinidae) and a predator Clitostethus arcuatus (Rossi) (Coleoptera: Coccinellidae) against the pomegranate whitefly, Siphoninus phillyreae (Haliday) (Homoptera: Aleyrodidae) on pomegranate (Punica granatum L.) by mass rearing and augmentative releases of these two natural enemies during a long-term field study in Egypt. A study was conducted to evaluate the biological control potential of this pest by augmentation with a parasitoid, En. inaron, and a predator, C. arcuatus. Both species were mass reared and monthly releases were made in fields of pomegranate during each of 11 consecutive years (1996–2006). About 1,155,000 En. inaron and 990,000 C. arcuatus were released in fields in Assuit governorate in Egypt on pomegranate which was naturally infested by S. phillyreae. Populations of the natural enemies and parasitism were much higher in field plots where releases were made compared with where no releases were made. The maximum rate of parasitism reached 93% (88% by En. inaron) in the field treatment where releases were made, while parasitism peaked at 36% where no releases were made. The population of En. inaron was significantly correlated with the population of whitefly during the field season. Additional parasitism was by natural infestation with Eretmocerus parasiphonini Evans and Abd-Rabou (Hyneoptera: Aphelinidae). Among all years, the maximum number of C. arcuatus ranged from 13 to 44 beetles per 100 leaves for the treatment, and there were more predators in the release plot than in the control plot. These observations enhance understanding of the usefulness of these natural enemies after augmentation in the field.

Biology and Feeding Behaviour of Ladybird,Clitostethus arcuatus, the Predator of the Ash Whitefly,Siphoninus phillyreae, in Fars Province, Iran

Clitostethus arcuatus (Rossi) (Coleoptera: Coccinellidae) is considered as one of the most important natural biological control agents of the ash whitefly, Siphoninus phillyreae (Haliday) (Hemiptera: Aleyrodidae) in Iran. In the current survey, the development, survival, longevity, fecundity, feeding behaviour, and population dynamics of the predator under laboratory and field conditions were studied. The longevity of female insects was significantly longer than that of males. Total feeding of 4th larval instars and females was significantly higher than males and other larval instars. The overall mortality rate from egg to adult under laboratory conditions was 22.7% while under field conditions it was 38.2%. Copulation lasted approximately 67 minutes while the average pre-mating and pre-oviposition times recorded were 3.8 and 1.8 days, respectively. The mean number of eggs laid by each female was 181. The adults could survive starvation for 4 days with a normal longevity of 62–73 days. The maximum population density of the predator was recorded in late August that coincided with the decline of the S. phillyreae population. C. arcuatus had four generations per year, and the adults were observed until mid December. Possible application of C. arcuatus for biological control of S. phillyreae in integrated pest management programs is discussed.

Predation of Clitostethus arcuatus (Col.: Coccinellidae) on Trialeurodes vaporariorum (Hem.: Aleyrodidae)

Greenhouse whitefly, Trialeurodes vaporariorum, is a serious pest of glasshouse crops. It shows resistance to different insecticides and growers are interested in finding other useful control methods. This research was carried out to study the predation potential and biology of Clitostethus arcuatus (Rossi) as one of the most important predators of this pest. Adult C. arcuatus were reared on tobacco leaves bearing colonies of greenhouse whitefly eggs under controlled conditions (25±2°C, 65±5% RH and 16 h L:8 h D). Results showed that the average developmental time of the egg, first through fourth instar larva and pupa were 2.82±0.12, 4.47±0.14, 4.54±0.1, 6.3±0.2, 7±0.22 and 3.8±0.13 days, respectively; and longevity of female and male were 66.4±2.6 and 54.9±2.5 days, respectively. The average feeding rates of female, male and larvae (first through fourth) were 61.4±0.7, 27.6±0.9 eggs/day and 12±1.03, 30.3±2.4, 41.3±2, 68.04±2 eggs/day, respectively. The larvae consumed an average of 992.2±36 eggs during the total larval developmental period with a daily mean of 45.8±0.5. A significant difference was shown between the feeding rate of fourth instar larval stages and between sexes. Females, males and one pair of C. arcuatus (♀,♂) consumed an average of 17.2±0.4, 10.6±0.8, 23.1±0.5 nymph/day; 28.5±0.9, 20.3±0.6, 47.2±0.6 pupa/day and 8±0.3, 6.5±0.54, 13.6±0.4 adult/day, respectively. The feeding rate was significantly different among whitefly life stages. Females laid an average of 3±0.23 eggs/day.

Temperature dependence for development of the whitefly predator Clitostethus arcuatus (Rossi)

This work aimed to study the biology of Clitostethus arcuatus (Rossi) (Cole- optera: Coccinellidae) under different temperatures and evaluate the optimum temperature for its mass rearing. Studies were carried out in the laboratory at four constant temperatures (158C, 208C, 258C and 308C), 75 ± 5% relative humidity and a photoperiod of 16 h light:8 h dark, in which C. arcuatus was fed ad libitum with nymphs of all instar of Aleyrodes proletella L. (Homoptera: Aleyrodidae) on Brassicae oleracea L. (var. Costata). The following biological parameters were evaluated: development time and survival rates of pre-imaginal stages, adult longevity (female and male), length of the pre-oviposition and oviposition periods, fecundity, fertility and percentage of egg hatching. Population growth parameters, the lower development threshold and the sum of effective temperatures were estimated. Temperatures ranging from 208 Ct o 308C were suitable for the development of C. arcuatus, suggesting that this species is well adapted to the temperatures usually found inside greenhouses or in open fields in temperate regions. Although the intrinsic rate of natural increase and doubling time were similar at 258C and 308C, the temperature of 258C was shown to be the most suitable for mass rearing and development of populations under field conditions, since the percentage of egg hatching and the accumulated survival rates of the pre-imaginal stages were the highest. Considering the estimated lower threshold for pre-imaginal development (7.98C) and the sum of effective temperatures (293.6 degree- days (8D)), it is predicted for Ponta Delgada (Azores, Portugal) that the first adults of C. arcuatus should emerge by the first fortnight of February and that up to 12 generations per year can occur.

The natural enemies of whiteflies (Hemiptera: Aleyrodidae) in southern Anatolia

In this study, a total of 48 natural enemies was found associated with 17 aleyrodid species from among the 26 aleyrodid species known from Southern Anatolia. In addition to these natural enemies, one species, Acletoxenus formosus Loew (Diptera: Drosophilidae), was identified as a first record for the Turkish fauna. The most common natural enemies, found on most whitefly species, were Cladosporum sp. (fungi), Chrysoperla carnea (Stephens) (Neuroptera: Chrysopidae), Conwentzia hageni Banks (Neuroptera: Coniopterygidae), Clitostethus arcuatus Rossi, Serangium montazerii Fürsch, Chilocorus bipustulatus L. (Coleoptera: Coccinellidae) and Encarsia inaron Walker (Hymenoptera: Aphelinidae).