Structure of egg‐batches of Thaumetopoea pityocampa (Den. and Schiff.) (Lep., Thaumetopoeidae), egg parasitoids and rate of egg parasitism on the Iberian Peninsula

Abstract

In four regions of the Iberian Peninsula 162 egg!batches of the pine processionary moth were collected after hatching of the caterpillars in 0880 and 0881[ After collection\ the batches were stored singly in test tubes closed with foam stoppers under laboratory conditions at 19Ð14>C[ The number of eggs in each egg!batch varied between 26 and 201 and the length of the batches between 9[5 and 3[1 cm[ Independently of the pine species infested\ seven to nine rows of eggs were counted\ wrapped around one pair of needles[ A correlation was found between number of eggs and the product of number of egg rows and length of egg!batches "71) ³ r 1 ³ 86)#[ Oviposition almost always started from the base towards the tip of the needles[ The egg parasitoids that emerged were counted daily\ removed and identi_ed[ Later in the year of oviposition\ after the end of the period of emergence of the parasitoids\ the scale cover of the egg! batches were removed[ One year later\ all eggs were opened and the contents\ such as parasitoid meconia and remains of caterpillars\ were determined[ The hatching rate of the caterpillars varied from 36[1 to 68[6)[ The rate of parasitism uctuated between 00[2 and 20[6)\ but 33) of parasitoids died before successful emergence[ Four species of Chal! cidoidea were identi_ed] Baryscapus servadeii "Dom[#\ Ooencyrtus pityocampae "Mercet#\ Anastatus bifasciatus "Fonsc[# and Trichogramma sp[ Baryscapus servadeii and O[ pityocampae were the most abundant species\ followed by Trich! ogramma sp[ Baryscapus servadeii emerged mainly in June and O[ pityocampae in April or June\ depending on the region[ For A[ bifasciatus only males\ and for B[ servadeii females emerged except one male[ In O[ pityocampae\ a relatively high percentage of males "4[3Ð09[3)# was found[

Establishment and expansion of a Thaumetopoea pityocampa (Den. & Schiff.) (Lep. Notodontidae) population with a shifted life cycle in a production pine forest, Central-Coastal Portugal

“…The hatching rate of both T. pityocampa populations in the Leiria Forest was in fact high -above 85% -when compared to egg-batches collected around the Mediterranean basin -15-80% -most mortality being due to parasitoids (Bellin et al, 1990;Tsankov et al, 1995;Tsankov et al, 1998;Schmidt et al, 1999). The SP egg mortality was the lowest ever found for the species, and most of the egg-batches had no parasitized eggs at all.…”

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

“…(1990) and Tsankov et al. (1999) for Greece, Halperin (1990b) for Israel and Schmidt et al. (1999) for the Iberian Peninsula.…”

“…For Italy, Tiberi (1990) reported a range of egg parasitoid impact from 6% to little more than 30%, depending on the region. On the Iberian Peninsula, egg parasitism ranged from 11.3 to 31.7% ( Schmidt et al., 1999). In Israel, relatively low rates of egg parasitism were reported by Halperin (1990b) and Kitt and Schmidt (1993) in T. wilkinsoni .…”

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.…”