![]() The females oviposit in the seeds contained in young cones, normally one egg per seed. In New Zealand the adults are on the wing from September to October (this varies according to the latitude). The head is white with dark jaws which in the larger larvae are noticeably toothed. ![]() The larva is a small, white, legless, wrinkled grub. The long upcurved ovipositor (egg-laying drill) of the female is a distinctive feature. Females are uniformly brownish-yellow whereas males are a lemon-yellow with black markings on the head. The forewings have a large black spot (stigma) near the leading edge. The small (3.0 - 3.5 mm long) adults have two pairs of transparent wings which appear to lack veins. The concentration of potential host material in seed orchards may result in an increase in numbers of this chalcid. spermotrophus will probably be felt more as increasing amounts of Douglas fir seed come from seed orchards rather than from seed collection in forests. A considerable amount of effort can be wasted collecting non-viable seed. Losses are worst in poor seed years as then the percentage of seed attacked is greatest. Generally the effect of this insect on Douglas fir seed-production is not great but locally in certain years the losses can exceed 20%. It is distributed throughout the country. Megastigmus spermotrophus probably became established in New Zealand in the 1920s, being introduced in the seed of Douglas fir. Pseudotsuga menziesii (Douglas fir) is the only host. The larvae of Megastigmus spermotrophus eat the contents of Douglas fir seed. 1 - Emergence holes of Megastigmus spermotrophus in Douglas fir seed. Insect: Megastigmus spermotrophus Wachtl (Hymenoptera: Chalcidoidea: Torymidae)įig. The information presented below arises from these research activities.įorest and Timber Insects in New Zealand No. The Rotorua-based Crown Research Institute continues to provide science that will protect all forests from damage caused by insect pests, pathogens and weeds. Scion is the leading provider of forest-related knowledge in New Zealandįormerly known as the Forest Research Institute, Scion has been a leader in research relating to forest health for over 50 years. ![]() Specialty Wood Products Partnership reports.Forest Practice Guides and Codes of Practice.Facts and Figures - NZ Plantation Forest Industry.Resource Catalogue ↓ ↑ Resource Catalogue.People and Places ↓ ↑ People and Places.Inventory and Decision Support Software.Forest Management ↓ ↑ Forest Management.Trees for Erosion Control/Soil Conservation. ![]()
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