Parasitism of egg‐batches of the pine processionary moth Thaumetopoea pityocampa (Den. & Schiff.) (Lep., Thaumetopoeidae) in various regions of Bulgaria¹

Abstract

In forests of Pinus nigra Arn. 147 egg‐batches of T. pityocampa were collected at different locations in Bulgaria in September‐October 1991 and March and June 1992. Directly after collection all batches were put singly into test tubes with cotton stoppers and stored under laboratory conditions at 20–22°C. Oviposition always started from the base towards the top of the needle. The emergence of egg parasitoids were controlled almost daily and they were counted and identified. The eggs from which parasitoids emerged were marked for further studies. After removing the scales and opening the eggs, the impact of the parasitoid species was evaluated by their meconia and remains. Ooencyrtus pityocampae (Mercet) was observed as the most abundant egg parasitoid, followed by Anastatus bifasciatus (Fonsc.) and Baryscapus servadeii (Dom.). The hyperparasitoid, Baryscapus transversalis Graham was recorded for the first time in Bulgaria and the polyphagous species Macroneura vesicularis (Retzius) was collected in Bulgaria for the first time from an egg‐batch of T. pityocampa. Trichogramma sp. was obtained in small amounts, too. Total mortality of host eggs varied from 34% to 48%; the mortality rate due to parasitism was 24.5% to 38.9%. The emergence dynamics of the egg parasitoids was studied under laboratory conditions, and the distribution of the egg parasitoids in the egg‐batches was recorded in detail. Additionally, the structure of the meconia of A. bifasciatus and M. vesicularis was described.

Egg parasitoids of Thaumetopoea pityocampa (Den. & Schiff.) (Lep., Thaumetopoeidae) and their impact in SW Turkey

“…The polyembryonic Trichogramma sp. (see also Tsankov et al., 1996a) attacked 1.8% of the eggs. Up to 20 (mean 12) dead pupae were found in one egg.…”

“…Since Halperin (1990a) showed that egg parasitoids of the processionary moth, T. wilkinsoni Tams, may be used for control, intensive work was performed in the last decade indicating the natural predation of the egg parasitoids in various Mediterranean countries. In SW Bulgaria the range of egg parasitism varied from 24.5 to 38.9% ( Tsankov et al., 1996a). Sometimes the attack can be reduced to 19.3% ( Tsankov et al., 1998).…”

“…Von der polyembryonalen Trichogramma sp. (siehe auch Tsankov et al., 1996a) wurden 1.8% der Eier der Gelege befallen; bis zu 20 (im Mittel 12) tote Puppen wurden in einem Wirtsei gefunden. In den untersuchten Gelegen befanden sich 2.9% unentwickelte Eier, und 0.6% waren völlig leer.…”

Incongruent evolutionary histories of two parasitoids in the Mediterranean Basin: influence of host specialization and ecological characteristics

“…This clade was represented by relatively few individuals in the central Balkans, where they were found in sympatry with individuals from CI, from which they were morphologically indistinguishable. Even though a dedicated taxonomic study would be necessary to reach a definitive conclusion, we suggest that they could correspond to a sister species of the ‘typical’ B. servadeii , possibly the cryptic hyperparasitoid Baryscapus transversalis Graham, 1991 (Tsankov et al ., ).…”

Tendency and consequences of superparasitism for the parasitoid Ooencyrtus pityocampae (Hymenoptera: Encyrtidae) in parasitizing a new laboratory host, Philosamia ricini (Lepidoptera: Saturniidae)

“…The fi tness of females is mainly dependent on their ability to fi nd hosts, and evaluating their life-history entails examining traits such as the percentage of eggs parasitized and percentage parasitoid emergence, development time, sex ratio and longevity (Bigler et al, 1991;Fournet et al, 2001;Perera & Hemachandra, 2014). The solitary synovigenic egg parasitoid Ooencyrtus pityocampae can be utilized in the biological control of the pine processionary moth due to its biological characteristics, which are as follows: it is successful in parasitizing this host both in the laboratory and the fi eld, has a short development time, long adult longevity, is able to successfully overwinter as a diapausing female and can locate its host by responding to its sex pheromone (Biliotti, 1958;Battisti et al, 1990;Tiberi, 1990;Tsankov et al, 1996Tsankov et al, , 1999Schmidt et al, 1997Schmidt et al, , 1999Mirchev et al, 2004). For this reason, successful mass and laboratory rearing of this parasitoid is very important.…”