Parasitoid Of Gypsy Moth Research Articles

An Old Remedy for a New Problem? Identification of Ooencyrtus kuvanae (Hymenoptera: Encyrtidae), an Egg Parasitoid of Lycorma delicatula (Hemiptera: Fulgoridae) in North America.

Spotted Lanternfly, Lycorma delicatula (White) is a recently introduced pest of Tree-of-Heaven, Ailanthus altissima (Mill.) Swingle in North America. Natural enemy surveys for this pest in Pennsylvania in 2016 recovered an encyrtid egg parasitoid from both field collections and laboratory rearing of field-collected L. delicatula egg masses. Both molecular and morphological data confirm that the egg parasitoids are Ooencyrtus kuvanae (Howard) (Hymenoptera: Encyrtidae). Ooencyrtus kuvanae (Howard) is primarily an egg parasitoid of gypsy moth, Lymantria dispar (L.), and was introduced to North America in 1908 for gypsy moth biological control. Although O. kuvanae is known to attack multiple host species, to our knowledge, this is the first report of O. kuvanae as a primary parasitoid of a non-lepidopteran host. Potential of O. kuvanae in the biological control of L. delicatula in North America and research needs are discussed.

Herbivore‐induced volatile emission in black poplar: regulation and role in attracting herbivore enemies

After herbivory, plants release volatile organic compounds from damaged foliage as well as from nearby undamaged leaves that attract herbivore enemies. Little is known about what controls the volatile emission differences between damaged and undamaged tissues and how these affect the orientation of herbivore enemies. We investigated volatile emission from damaged and adjacent undamaged foliage of black poplar (Populus nigra) after herbivory by gypsy moth (Lymantria dispar) caterpillars and determined the compounds mediating the attraction of the gypsy moth parasitoid Glyptapanteles liparidis (Braconidae). Female parasitoids were more attracted to gypsy moth-damaged leaves than to adjacent non-damaged leaves. The most characteristic volatiles of damaged versus neighbouring undamaged leaves included terpenes, green leaf volatiles and nitrogen-containing compounds, such as aldoximes and nitriles. Electrophysiological recordings and olfactometer bioassays demonstrated the importance of nitrogenous volatiles. Under field conditions, parasitic Hymenoptera were more attracted to traps baited with these substances than most other compounds. The differences in volatile emission profiles between damaged and undamaged foliage appear to be regulated by jasmonate signalling and the local activation of volatile biosynthesis. We conclude that characteristic volatiles from damaged black poplar foliage are essential cues enabling parasitoids to find their hosts.

Gypsy moth parasitoids in the declining outbreak in Lithuania

A 3 year study was conducted on the parasitoids of gypsy moth larvae in two reducing outbreak areas in Lithuania. Overall parasitism of 25.0 ± 2.0% in the first post‐culmination year was significantly lower than the 36.3 ± 1.4 and 35.2 ± 1.4% parasitism in the two subsequent years. When analysed in terms of the life stage at which the host was collected, the total parasitism over 3 years was constantly increasing from 3.1 ± 0.8 in the first to 72.5 ± 2.9% in the sixth instar. Parasetigena silvestris R.‐D. dominated causing 48.7 ± 1.5% parasitism and 16.7 ± 0.6% larval mortality preferably in late instars. Phobocampe disparis Vier. contributed to 21.9 ± 1.2% parasitism and 7.5 ± 0.5% mortality recovering from early instar larvae. Meteorus pulchricornis Wes. parasitized 4.3 ± 0.6% gypsy moth larvae causing 1.5 ± 0.2% mortality and a few Apanteles species provided 2.8 ± 0.6% parasitism and 1.0 ± 0.2% mortality. The gypsy moth in Lithuania was reported to act as host for Rogas sp. (Hym., Braconidae) and Siphona boreata Mes. (Dipt., Tachinidae).

Influence of host deprivation on egg load and oviposition behaviour of Brachymeria intermedia, a parasitoid of gypsy moth

Abstract. Mated female Brachymeria intermedia (Hymenoptera: Chalcididae) deprived, since emergence, from pupae of their host Lymantria dispar (Lepidoptera: Lymantriidae), accumulated eggs but had a very low rate of hostacceptance. Parasitoids that were host‐deprived after encountering pupae early in life also accumulated eggs, but maintained a high acceptance rate. Thus early exposure to hosts promoted active reproductive behaviour. Total egg production depended on the total number of pupae encountered, indicating that B.intermedia adjust their egg production to host availability. Hence, in B. intermedia both the physiological state of the parasitoid (age and egg load) and the informational state (in this case host‐availability and experience) interact to shape oviposition behaviour.

European field collections and Canadian releases ofCeranthia samarensis (Dipt.: Tachinidae), a parasitoid of the gypsy moth

A programme to collect, import and release into Canada the gypsy moth parasitoid,Ceranthia samarensis (Diptera: Tachinidae) is described. The parasitoid's potential for biological control in Canada is also discussed.

Host Plants Used by Gypsy Moths Affect Survival and Development of the Parasitoid Cotesi melanoscela

The effects of short-term phenological changes in different tree species on development and survival of the gypsy moth parasitoid Cotesia melanoscela (Ratz.) are examined. Larvae stung by C. melanoscela and an unstung control group were allowed to develop on foliage from four tree species (red maple, mockernut hickory, American beech, and white oak) started on five different dates during a 16-d period after bud break. Survival of Cotesia larvae declined Significantly with start date on all four species; however, white oak supported high wasp survival for most of the period. Wasp development time also increased significantly with increasing start date on each species. Stung larvae suffered significantly higher mortality from causes other than wasp emergence than did control larvae. The implications for underestimating mortality attributable to parasite attack are discussed. In particular, C. melanoscela probably causes significantly greater mortality of gypsy moth larvae than estimated from parasite emergence.

Effects of Light on Location of Host Egg Masses by Ooencyrtus kuvanae (Hymenoptera: Encyrtidae), an Egg Parasite of Gypsy Moth (Lepidoptera: Lymantriidae)

The effect of light on host finding and parasitism by Ooencyrtus kuvanae (Howard), an egg parasitoid of gypsy moth, Lymantria dispar L., was studied in the laboratory. Parasitism by O. kuvanae females confined in light or dark cylinders was not significantly different. When parasites were given a choice between light or dark chambers, significantly more chose the light chamber regardless of the presence or absence of an egg mass. However, chambers were significantly more attractive when they contained an egg mass, indicating that an egg mass contributes to host location over short distances. Parasitism of egg masses in dark chambers in which no O. kuvanae were found demonstrates that the parasite may leave these sites after oviposition. Implications for success of O. kuvanae in low-density gypsy moth populations are discussed.

Pheromonal basis of courtship behavior in two gypsy moth parasitoids:Brachymeria intermedia (Nees) andBrachymeria lasus (Walker) (Hymenoptera: Chalcididae)

The pheromonal basis of the courtship behavior of two gypsy moth parasitoids,Brachymeria intermedia andBrachymeria lasus, was traced to a single component in each case. This component was isolated by a combination of absorption and gas-liquid chromatography and shown to elicit some of the courtship behavior typical of these species. Bioassays of extracts from several independent techniques for sequestering pheromones, as well as interspecific assays, support this conclusion. Comparative analyses of both male and female extracts by capillary chromatography show the uniqueness of the pheromonal peak to the female volatile profile.

Field confirmation of a mechanism causing synergism between Bacillus thuringiensis and the gypsy moth parasitoid, Apanteles melanoscelus

In 16-ha plots aerially sprayed with single and double applications of Bacillus thuringiensis, percentage parasitism by A. melanoscelus and the number of A. melanoscelus cocoons under burlap strips were higher than in comparable untreated plots in the same area. Strong correlations occurred between percentage parasitism and caterpillar size, with plots having the smallest caterpillars being the most heavily parasitized. However, these parameters were also negatively correlated with number of caterpillars per plot. The increased numbers of parasitoid progeny, i.e., cocoons, found in treated plots showed that corresponding increases in percentage parasitism could not be due simply to improved parasitoid: host ratios. Evidence strongly suggests that the retarding effect of B. thuringiensis infection kept gypsy moth larvae small enough in the treated plots to permit A. melanoscelus females to parasitize relatively large numbers of caterpillars.

Comparative Behavioral Responses of Three Brachymeria1 Species and Other Gypsy Moth 2 Parasitoids to Humidity and Temperature

The behavioral responses of Brachymeria intermedia (Nees), B. lasus (Walker), and B . sp. (Hymenoptera: Chalcididae) to humidity and temperature gradients were measured and compared to that of other gypsy moth, Lymantria dispar (L.) (Lepidoptera: Lymantriidae), parasitoids; namely, Apanteles melanoscelus (Ratzeburg) and A . sp. (Hymenoptera: Braconidae), Eurytoma verticillata (F.) (Hymenoptera: Eurytomidae), Gelis tenellus (Say) (Hymenoptera: Ichneumonidae), and Compsilura concinnata (Meigen) (Diptera: Tachinidae). Brachymeria spp. preferred lower humidities and higher temperatures than the other parasitoids but did not differ noticeably from each other. As the established species, B. intermedia . is found primarily in sunny habitats, it is likely that B. lasus and B . sp., which are exotic species not yet released in North America, have the same habitat preferences. This has implications for their effectiveness as gypsy moth parasitoids.

R and K strategies in some larval and pupal parasitoids of the gypsy moth.

The investigations of the bionomics and parasitoid-host interactions of some gypsy moth parasitoids provide an opportunity to consider the role of r and K strategies in the life history of some tachinid and hymenopterous parasitoid species. Available historic data as well as results of recent studies are utilized in an attempt to evaluate the degree to which the data conform to this paradigm. Few studies have provided the information required to evaluate this concept particularly in a parasitoid complex. The concept of r and K also is discussed in relation to biological control strategies, and the implications of this analysis for those arguments are discussed.

The Gypsy Moth Parasitoid Complex in Western Massachusetts: A Study of Parasitoids in Areas of High and Low Host Density 1

Compsilura concinnata (Meigen), Blepharipa scutellata (Robineau-Desvoidy) and Apanteles melanoscelus (Ratzeburg) were the dominant species in both the low eggmass density site (Cadwell Memorial Forest) and the high egg-mass density site (Ludlow Town Forest). Compsilura concinnata parasitized a greater proportion of the larvae occurring in the lower canopy of oak. Although no vertical stratification was noted for parasitism by Blepharipa scutellata , it was more prevalent in the low density site. Other parasitoids occurring in the sites studied included Phobocampe disparis (Vier.), Parasetigena agilis (Robineau-Desvoidy) and Exorista sp. These occurred in low numbers.

Hybridization of Strains of the Gypsy Moth Parasitoid, Apanteles melanoscelus,1 and its Influence upon Diapause

Colonies of Apanteles melanoscelus (Ratzeburg) from France, Yugoslavia, and Connecticut were crossed and photoresponse curves were obtained for the 3 strains and their hybrids under laboratory and outdoor insectary conditions. Photoperiodic responses of the Connecticut strain were different from the French and Yugoslavian parasites and their hybrid. The triple hybrid was different from the French, Yugoslavian, or Connecticut strains in its diapause characteristics. The laboratory-determined critical photophases at 24°C were: Connecticut, 16-17 h; the French-Yugoslavian-Connecticut hybrid, 15 h ; French, Yugoslavian and the French-Yugoslavian hybrid, 12.5-13.5 h. Under outdoor insectary conditions, the average percentage entering diapause for each strain was: Connecticut, 96%; a newly-collected French colony, 99%; a laboratory French colony, 8% ; Yugoslavian, 8% ; French-Yugoslavian hybrid, 7%; and French-Yugoslavian-Connecticut hybrid, 30%.