Dasineura Mali Research Articles

Trapping <I>Dasinuera mali</I> (Diptera: Cecidomyiidae) in Apples

The midge Dasineura mali (Kieffer) (Diptera: Cecidomyiidae) is a significant pest of apples (Malus spp.), and the recent identification of the female sex pheromone is enabling new direct control tactics to be considered. Direct control using male suppression will require knowledge of the frequency of multiple mating, dispersal and colonization rates, and the efficiency of male removal. Males were able to mate up to five times, with a mean of 2.7 times when presented in a 10 female-to-1 male group, designed to simulate male suppression. Male catch in response to the pheromone loading was curvilinear over 4 orders of magnitude from 3 microg to 30 mg on rubber septa. Trapping using a high-dose pheromone lure was combined with oil-based traps similar to the inexpensive New Zealand "Lynfield trap" used for tephritid surveillance, to test male suppression in young orchard blocks at 500 traps per ha. Monitoring traps indicated 96% lower catch in the treated plots compared with control plots, over 137 d. However, a lack of shoot tip infestation in both treated and untreated plots indicated limited colonization and prevented an assessment of potential population suppression. Furthermore, a contribution to these results from communication disruption cannot be ruled out. Replicated transects of frequency of infested shoots from a mature orchard across the adjacent young block confirmed that colonization by ovipositing females was essentially limited to the first 30 m.

Phenology of apple leafcurling midge (<i>Dasineura mali</i>) in relation to parasitism by <i>Platygaster demades</i>

The phenology of apple leafcurling midge (ALCM Dasineura mali) and that of its parasitoid Platygaster demades was monitored in orchards over several years in the Nelson district There were 45 generations of ALCM the first two being distinct while the following generations tended to overlap Host and parasitoid populations were generally synchronized except for the second generation when parasitoid numbers were low and parasitism levels dropped Midge populations increased rapidly at this time and remained high in subsequent generations despite moderate levels of parasitism Laboratory studies on the effect of temperature on host and parasitoid pupal development rates combined with weather station data and actual soil temperatures were used to develop a model to predict generation timing Platygaster demades adults had a longer development period and emerged later than ALCM adults The influence of host and parasitoid phenology on parasitism levels and biological control of ALCM is discussed

Flight Activity and Further Evidence for a Female-Produced Sex Pheromone of the Apple Leaf Midge, Dasineura mali, in Nova Scotia

The flight activity of the apple leaf midge, Dasineura mali (Kieffer), was determined in the field and laboratory. Males and females began emerging at the onset of the photophase. In the field, delta-shaped traps baited with 6 virgin females caught males exclusively, with the most abundant catches on the ground as compared to those at 1 and 2 m. Most males were captured at 1100 hours and males remained in the vegetation under the trees throughout the day. Sweep netting revealed that conspecifics mate in the vegetation under orchard trees in the morning hours, and females move from the ground to the orchard canopy to oviposit at 1000 hours. Gas chromatographic-electroantennographic detection (GC-EAD) analyses indicated the presence of an electrophysiologically active compound in solid phase microextraction (SPME) effluvial collections and pheromone gland extractions from virgin females.

The impact of early season insecticides on biological control of apple leafcurling midge (<i>Dasineura mali</i>)

The fate of apple leafcurling midge (ALCM Dasineura mali) egg batches was monitored in spring 2003 at two apple orchards in Riwaka near Motueka Orchard A had received prebloom insecticide applications of chlorpyrifos and carbaryl for fruit thinning each season since 2000 Orchard B substituted these chemicals with the selective insecticide buprofezin and used benzyladenine for fruit thinning over the same period Predation and parasitism of ALCM eggs at orchard B resulted in lower survival of larvae and less damage to shoots compared to orchard A Ninety percent of ALCM larvae at orchard B were parasitised by Platygaster demades compared with only 3 at orchard A Heavy infestation of shoots by second generation midge larvae at orchard A resulted in premature termination of 69 of growing shoot tips These results suggest that nonselective early season insecticides used in pipfruit spray programmes may disrupt biological control of ALCM

Emergence of apple leafcurling midge (<i>Dasineura mali</i>) and its parasitoid (<i>Platygaster demades</i>)

Apple leafcurling midge (Dasineura mali) (ALCM) can seriously damage apple tree leaves Insecticides may be applied to the soil in spring to kill ALCM emerging from overwintering sites ALCM emergence was studied in the Waikato Hawkes Bay Nelson Canterbury and Central Otago over two seasons (1998/99 and 1999/ 2000) using cages placed over the soil beneath apple trees ALCM and its egg parasitoid (Platygaster demades) emerged over a similar period of time Emergence in southern districts began later and over a shorter period A single soil treatment with diazinon reduced the numbers of ALCM emerging from treated soil but also very few P demades emerged

Adult Emergence and Reproductive Behavior of the Leafcurling Midge Dasineura mali (Diptera: Cecidomyiidae)

The leafcurling midges Dasineura mali Kieffer collected as mature larvae in curled apple leaves were brought to the laboratory where they left leaves and pupated in boxes of soil. Two to 3 wk later, adult eclosion showed a diel periodicity, peak eclosion occurring between 0600 and 1000 hours. Within this period, peak male eclosion typically occurred 1–2.5 h earlier than peak female eclosion. For males, wing fanning, mating, and flight first occurred, on average, 30, 32, and 41 min after eclosion, respectively. For virgin females, calling behavior and mating first occurred, on average, 16 and 38 min after eclosion, respectively. Calling events were of variable duration (0.3–55 min) and occurred most frequently between 0900 and 1500 hours. Males mated many times, whereas females mated only once or twice. After mating, females sat for ≈1 h before taking their 1st flight. In a windtunnel, percentages of females taking-off, flying upwind, and exhibiting examining behaviors on apple leaves increased from the morning to the afternoon. In an apple orchard, traps placed below the canopy of trees caught more males than traps placed in the tree canopy. The relevance of this information for the isolation and identification of behaviorally active chemicals (i.e., pheromones and kairomones) is discussed.

Development of Orius vicinus (Ribaut) (Heteroptera: Anthocoridae) on Different Prey

The survival, development and adult size of Orius vicinus were studied on five prey species, the mites Aculus schlechtendali, Panonychus ulmi and Tetranychus urticae, and larvae of the insects Dasineura mali and Thrips obscuratus. Survival was high (74-100%) and O. vicinus was able to complete development on all prey species in an average of 22-26 days at 20 C. The most rapid development occurred on T. obscuratus, T. urticae and P. ulmi. Adult size was estimated from the length of the fifth instar cast skin, which averaged 2.18 to 2.48 mm on different prey. The largest bugs were obtained from feeding on T. obscuratus or D. mali. O. vicinus, which were fed A. schlechtendali, were the slowest to develop and produced the smallest adults. The results are discussed in relation to prey availability and observed predation in the field, and are compared with previous feeding studies.

Role of apple leafcurling midge in the spread of fire blight

The incidence of apple leafcurling midge (Dasineura mali) (ALCM) infestations in association with fire blight (Erwinia amylovora) was monitored in the 1997-98 season. In two blocks of MM106 apple rootstocks, increased fire blight incidence coincided with severe outbreaks of ALCM. Rain did not occur prior to severe outbreaks of both pests. Trees with no ALCM infestation did not develop fire blight, while 61.7% of those with ALCM infestation subsequently developed fire blight. ALCM damage to leaves predisposed them to fire blight infection. These findings provide the first quantitative evidence that ALCM may be involved in the spread of fire blight.

Target and non-target impacts from diazinon applied against <i>Dasineura mali</i> in a Canterbury apple orchard

The control of apple leafcurling midge (Dasineura mali) with diazinon was investigated as part of an Integrated Fruit Production programme. A soil drench was applied against the emerging adults of the first generation (pre-flowering), and compared with a foliar application against the second generation (early December). Nontarget effects on the biodiversity of ground dwelling arthropods were examined using pitfall traps before and after diazinon applications, and on arboreal diversity using brushed leaf samples. Drench, foliar spray, and a combination of these treatments, all reduced percentage of damaged shoots compared to untreated plots. Drench and foliar applications gave similar results. Little impact on ground-dwelling arthropod biodiversity was detected following the drench or foliar applications. The biodiversity of foliage-dwelling (mainly beneficial) arthropods showed a significant reduction after foliar treatment.

Soil degradation of diazinon and its effect on the emergence of apple leafcurling midge

The degradation of diazinon residues in the soil of an orchard on the Waimea Plains, Nelson was determined. The half life of diazinon varied significantly between 12.2 and 27.7 days, depending on the time of application. Soil applications of diazinon had a significant effect on the emergence of adult apple leafcurling midge (ALM) (Dasineura mali Diptera: Cecidomyiidae). More ALM were captured in the control and plots treated with diazinon on 7 September than in plots treated with diazinon on 21 September and 5 October.

EVIDENCE FOR A FEMALE-PRODUCED SEX PHEROMONE IN THE APPLE LEAF MIDGE, DASINEURA MALI (KIEFFER) (DIPTERA: CECIDOMYIIDAE)

The apple leaf midge, Dasineura mali (Kieffer), is an apple pest in Nova Scotia's Annapolis Valley (Rogers 1991). Larval D. mali are specialist, leaf-feeding pests that attack primarily young pubescent apple shoots. Larval feeding induces the leaves to curl tightly toward the midrib and form distinctive reddish galls that desiccate following larval exit. Economic damage to orchards in Annapolis Valley has not been estimated, but immature trees and nursery stock are vulnerable because new growth is essential for proper tree formation (Rogers 1991).

Plant Volatiles Mediate Host-Finding Behavior of the Apple Leafcurling Midge

The behavioral responses of apple leafcurling midge,Dasineura mali Kieffer, mated females to foliage from host and nonhost trees were investigated in a wind tunnel. When released downwind of apple or pear foliage, females exposed to apple were more likely to exhibit upwind flight and to approach and land on foliage. On apple foliage, landings were concentrated on buds and immature leaves. Probability of taking flight and latency to flight did not differ for females exposed to apple and pear. When foliage was placed behind screens to obscure plant visual stimuli, females again distinguished between apple and pear, with more of the females exposed to apple odors flying upwind and landing. Females exposed to pear odors were more likely to fly upwind, approach, and land than females exposed to clean air. Odors from immature apple foliage triggered orientation responses in a larger percentage of females than odors from mature apple foliage. A dichloromethane extract of immature apple foliage also triggered orientation responses.

Apple leafcurling midge egg laying on different apple cultivars and orchard properties on the Waimea plains, Nelson

During the 1995-96 and 1996-97 growing seasons, regular monitoring of apple leafcurling midge (ALM) (Dasineura mali Diptera: Cecidomyiidae) egg laying was conducted in three conventionallymanaged orchard properties on the Waimea Plains, Nelson. The percentage of apple shoots infested with ALM eggs fluctuated considerably between seasons. The timing of egg laying peaks was similar between orchard properties, but differed between cultivars. Peak egg laying periods occurred 7-14 days earlier on ‘Royal Gala’ compared with ‘Braeburn’. No notable difference in the level of apple shoot tips infested with ALM eggs occurred between cultivars. Similarly, no orchard property had consistently higher or lower levels of shoot tips infested with ALM eggs during the season. The importance of these findings for monitoring ALM is discussed briefly. apple leafcurling midge, Dasineura mali, egg laying, apple cultivar, monitoring

Detection and distribution of the Apple Leaf Midge, Dasineura mali, in Nova Scotia

Detection and distribution of the Apple Leaf Midge, Dasineura mali, in Nova Scotia

Woolly Apple Aphid Outbreak Following Use of Fenvalerate in Apples in Canterbury, New Zealand1

Substitution of the synthetic pyrethroid, fenvalerate, for azinphosmethyl in an apple orchard spray program led to an outbreak of Eriosoma lanigerum (Hausmann) within a single season of use. Aphid colonies on water sprouts of cv ‘Cox’s Orange Pippin’ had a mean of 7.88 colonies/water sprout by Dec. 12, 1978, in the fenvalerate treated block compared with 0.08 colonies under azinphosmethyl treatment. This was due to the low toxicity of fenvalerate compared with azinphosmethyl as shown in laboratory tests: Survival of treated colonies was 77.7 and 33.4%, respectively, with fenvalerate and azinphosmethyl. A midge, Dasineura mali Kieffer, also became much more prevalent under the fenvalerate treatment with 75% of water sprouts infested by mid-February 1979 compared with 14% in the azinphosmethyl block.

THE APPLE LEAF MIDGE, DASINEURA MALI (DIPTERA: CECIDOMYIIDAE), IN NEW BRUNSWICK APPLE ORCHARDS

The apple leaf midge, Dasineura mali (Kief.), was first noted in a New Brunswick commercial apple orchard at Waweig, Charlotte County, in 1964. Adults collected there in 1965 were identified by Biosystematics Research Institute. The midge's first appearance in the Saint John River Valley was in 1968 in York County. Since 1968 this insect has spread to infest orchards up river as far as Woodstock and down river to orchards in the Gagetown-Queenstown area.