Leafminer Parasitoid Research Articles

Analysis of searching movements of a leafminer parasitoid in a structured environment

ABSTRACT. Pnigalio soemius (Hymenoptera, Eulophidae) is a polyphagous ectoparasitoid of the apple leafminer Phyllonorycter cydo‐niella (Lepidoptera, Gracillaridae). The tracks of females searching on the unmined leaf lamina and on the mine were segmented into 2 mm steps and analysed for angle distributions and correlations between successive steps. The movements on the mine are characterized by a higher mean and higher variance of turn angles compared to the turn angles on the leaf (kinesis‐reaction family). Both klinokinesis and schemakinesis, for which a more precise definition is proposed, are present. Varying the step length has a great influence on the result and can be used to identify different orientation reactions within one track. The insect turns sharply once the mine border has been reached, a behaviour shown to be a crude taxis. An ecologically related species, Sympiesis sericeicornis (Hymenoptera, Eulophidae), moves in the same way. For this species a taxis towards the host could also be observed. A complex mixture of these orientation behaviours allows the parasitoid to remain on the mine and to localise the host.

Influence of Host Crop on Parasitoids (Hymenoptera) of Liriomyza spp. (Diptera: Agromyzidae)

Predominant parasitoids reared from the four major Liriomyza spp. Infesting 12 different host crops in North America and Hawaii are reviewed. No single parasitoid species was found to be the predominant biological control agent in most crops. Diglyphus begini (Ashmead), Halticoptera circulus (Walker), and Chrysonotomyia punctiventris (Crawford) were either the first or second most reared species in 60.9, 26.1, and 21.7% of o the studies, respectively. Because of uneven distribution of parasitoids among crops, it is suggested that effective biological control may depend on matching the “most effective” parasitoid species complex with a given Liriomyza host and crop. Introduction and augmentation strategies for leafminer parasitoids are suggested.

ABUNDANCE AND PHENOLOGY OF PARASITOIDS OF THE SPOTTED TENTIFORM LEAFMINER, PHYLLONORYCTER BLANCARDELLA (LEPIDOPTERA: GRACILLARIIDAE), IN CONNECTICUT

AbstractParasitoids of the trivoltine spotted tentiform leafminer, Phyllonorycter blancardella (Fabr.), were studied in Connecticut apple orchards to determine their relative importance, emergence patterns, and seasonal abundance. Sixteen parasitoid species, including 12 eulophids, emerged from mines formed by 4th- and 5th-instar leafminer larvae. The species were primary, secondary, or facultative secondary parasitoids. Five were new records. The braconid Pholetesor ornigis (Weed) was the most abundant in the first and third leafminer generations, and the eulophid Sympiesis marylandensis Girault was the most abundant in the second generation. Ratios of parasitoids to Phyllonorycter spp. were generally higher in samples from unsprayed trees than in those from sprayed trees. Major parasitoids usually emerged 1 to 4 wk before their larval hosts became plentiful. Sweep samples indicated relatively high abundance of one or both major parasitoids during the first and second leafminer generations. Monitoring of parasitoids and the judicious use of insecticides may have a critical role in pest management programs utilizing native parasitoids of leafminers.

Citrus Leafminer Parasitoid, Ageniaspis citricola Logvinovskaya (Insecta: Hymenoptera: Encyrtidae)

The encyrtid parasitoid Ageniaspis citricola was first imported into Florida from Australia in 1994 in a classical biological control program against the citrus leafminer, Phyllocnistis citrella Stainton (Hoy and Nguyen 1994a). A second strain of Ageniaspis citricola was introduced into Florida from Taiwan in 1997, although there is no evidence that this second strain ever established (Hoy and Nguyen 1997). The citrus leafminer was first detected in Florida in 1993, and quickly spread throughout all 860,000 acres of citrus, posing a serious threat to the state's citrus industry. The population of A. citricola from Australia quickly established and dispersed throughout the state, reaching parasitism levels near 100% in some areas (Hoy et al. 1995ab, Knapp et al. 1995, Bullock et al. 1996, Pomerinke and Stansly 1998). Ageniaspis citricola is consistently the dominant parasitoid of citrus leafminer in Florida. This document is EENY-285 one of a series of Featured Creatures from the Entomology and Nematology Department, Florida Cooperative Extension Service, Institute of Food and Agricultural Sciences, University of Florida. Published: March 2003.
 EENY-285/IN561: Citrus Leafminer Parasitoid, Ageniaspis citricola Logvinovskaya (Insecta: Hymenoptera: Encyrtidae) (ufl.edu)