New Pest Response Guidelines - aphis - US Department of Agriculture

Control Procedures
Larval Parasitoids
The impact of parasitoids on the larval stage differs with the level of outbreak
and location of insect species determining the effectiveness of these natural
regulators upon pest population density. A listing of the more important
Dendrolimus parasites is provided in Appendix A.
Dendrolimus pini
Numerous parasitic insects have been noted to attack PTL larvae including
Agria (Pseudosarcophaga) affinis (Fallen), Nemorilla floralis (Fallen) and
Sturmia inconspicua (Meigen), Tricolyga segregata Rondani, Sarcophaga dux
(Thompson), Tachina (Exorista) larvarum (L.), and a braconid of the genus
Apanteles (Melis, 1940).
For example, A. affinis reduced numbers of PTL larvae and pupae by 10% to
40% in Poland (Sitowski 1928). In 1947-48 and 1956-57, because of high
parasitism of pine moth larvae by Apanteles sp. and Meteorus sp., the Polish
forest administration decided not to initiate control treatments (Sliwa 1992). In
stands where sticky bands were used as a method of PTL control, Muscina
pabulorum Fallen parasitized 40-to 60% of pine moth larvae in the first year
and Stomoxys calcitrans L. parasitized up to 30% of the larvae (Sierpinska,
1998).
Dendrolimus punctatus
Ichneumonid wasps are important parasitoids of the larvae and pupae of
Masson pine caterpillar. A study from China conducted from 1983 to 1984
found parasitism by Casinaria nigripes (Gravenhorst) to be an important factor
in mortality of the MPC. The ichneumonid had five generations a year and
overwintered in the larval stage in the third to fourth larval instar of the host
(Qian, 1987). C. nigripes parasitism was reported to range from 67%
parasitism in Hunan province (Ma et al.,1989) to 23% to the third generation of
D. punctatus in Jiangsu province (Qian, 1987; CABI, 2011b).
The uji fly, Blepharipa zebina Walker, is commonly found in MPC larvae and
pupae (CABI, 2011b). Wong and Zhou (1995) reported parasitic rates by
Carcelia matsukarehae Shima, B. zebina and Sarcophaga beesoni Senior-
White on the second generation of MPC as 14, 16, and 34%, respectively, in
Guangdong province. The tachinid Exorista xanthaspis (Wiedemann) is
another parasitoid of the forest pest of MPC. Having five to six generations a
year, parasitism of MPC in the first, second and third generations was 22, 45
and 1%, respectively. Most of the eggs were laid on the hosts' prothoracic legs,
with 1 to 33 eggs being placed on each host. Some of the hosts (3%) were able
to survive parasitism if they had an average of 2.5 eggs or less. In the field in
China fluctuations in the parasitoid population were positively correlated with
temperature during May but negatively correlated in late July to early August
(Ma et al., 1988).
6-10 Dendrolimus Pine Moths 12/2012-01