II.Bionomics of Aphides 2.Population Dynamics Body is diminuitive,but has a high reproduction rate.4-5 nymphs produced by a cotton aphid daily under a suitable environment. 60-70 nymphs produced by a female in a lifetime.More than 10-20 generations annually for most aphids
2. Population Dynamics • Body is diminuitive, but has a high reproduction rate. 4-5 nymphs produced by a cotton aphid daily under a suitable environment. • 60-70 nymphs produced by a female in a lifetime. More than 10-20 generations annually for most aphids. Ⅱ. Bionomics of Aphides . Bionomics of Aphides
3.Factors Influencing Population Dynamics 1)Climate Conditions Temperature:Prefer higher temperatures. Humidity:Cause severe damage to plants during droughts. Color preferences:Yellow;negative tropism to silver-gray. Wind:Influences distribution and activity
3. Factors Influencing Population Dynamics 1) Climate Conditions Temperature: Prefer higher temperatures. Humidity: Cause severe damage to plants during droughts. Color preferences: Yellow; negative tropism to silver-gray. Wind: Influences distribution and activity
2)Food and nutrition Some aphids are polyphagous,e.g., cotton aphids,green peach aphids.But a few aphids are of specific plants,.eg,梨二叉蚜m tree;phylloxera(葡萄相 grape vines
2) Food and nutrition Some aphids are polyphagous, e.g., cotton aphids, green peach aphids. But a few aphids are of specific plants, e.g., 梨二叉蚜 mainly damage pear tree; phylloxera (葡萄根瘤蚜) only feed on grape vines
3)Natural Enemies ◆ Pathogens:蚜霉菌属。 Parasitic insect natural enemies: Aphidiidae(蚜茧蜂科)and Chalcididae(小 蜂科) ◆ Predatory insects:syrphids,lady beetles, lacewings,aphid-feeding cecidomyds etc. 4)Human factors Spraying insecticides
3) Natural Enemies Pathogens: 蚜霉菌属。 Parasitic insect natural enemies: Aphidiidae (蚜茧蜂科) and Chalcididae ( 小 蜂科). Predatory insects: syrphids, lady beetles, lacewings, aphid-feeding cecidomyds etc. 4) Human factors Spraying insecticides
III.Aphids of Cereal Crops Damage mainly cereal crops such as wheat,corn,sorghum,etc.They are all in Homoptera,Aphididae. 麦无网长管蚜
Ⅲ. Aphids of Cereal Crops . Aphids of Cereal Crops Damage mainly cereal crops such as wheat, corn, sorghum, etc. They are all in Homoptera, Aphididae