8 things you didn't know about aphids

1. They are born pregnant

Most aphid species are born with another clone inside of its body. They will start producing clones just 7 days after being born and will birth up to 80 clones in its life span.

2. They've made a pact with Ants

Some ant species have a mutualistic relationship with aphids. Ants protect the aphids from predators in exchange for their honeydew secretions (aphid poop). This may seem like a mutually beneficial relationship but some studies have shown that ants will prevent the aphids from leaving the plant in order to secure the honeydew supply. This is achieved by releasing semiochemical that inhibit the growth of wings or clipping them off to prevent aphids from escaping. [1],[2] The relationship between ants and aphids is a complicated one and requires further studies in order for us to fully understand it.

3. Most species are chemical resistant

Insecticide resistance is a big problem when it comes to common pests. Aphids are genetic masters with an outstanding ability to adapt to harsh environments. Due to these characteristics, they can develop resistance to insecticides rapidly. In fact, one of the most widespread aphids (green peach aphid) is resistant to over 70 different insecticides and its resistance mechanisms keep getting better overtime. [3]

4. They are all tiny clones of their mothers

Aphids have one of the most fascinating life cycles. Depending on the species, Aphids can lay eggs or birth live clones based on environmental cues. Usually when winter is around the corner, aphids will switch from birthing live clones to laying eggs that will overwinter and hatch in spring.

5. They send alarm signals to other aphids when in danger

It’s a common practice among insects to communicate with each other through pheromones. When an aphid is in danger it releases pheromones to alert the surrounding aphids. In response, the aphids will attempt to escape by dropping to the ground or walking away from the area.

6. They can change their color to look less appealing to predators

Aphids can use color polymorphism by producing carotenoids in their body. Carotenoids are the bright yellow, red, orange pigments we see in our vegetables. Production of carotenoids is usually only available in plants, fungi, and other microorganisms. Aphids have found a way to integrate genes with fungi in order to gain this ability.[4] 

7. They can grow wings and fly away when it gets too crowded.

Also known as wing polypheniesm. Aphids can produce winged or wingless clones in response to environmental cues. These cues can be overcrowded conditions, lack of healthy leaves, or presence of natural enemies. [5]

8. They don't need a male to reproduce

Aphids can either have a holocyclic or anholocyclic life cycle depending on the species. The anholocyclic life cycle is completed in complete absence of males. The aphids are all females and only birth females throughout the year. In the holocyclic life cycle aphids give birth to live clones during the summer/spring time. Once the weather cools down the aphids will start to produce male offspring and switch to laying eggs instead of birthing live clones. These eggs overwinter and hatch in the spring time!

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[1] Oliver, T. H., Mashanova, A., Leather, S. R., Cook, J. M., & Jansen, V. A. (2007). Ant semiochemicals limit apterous aphid dispersal. Proceedings of the Royal Society B: Biological Sciences, 274(1629), 3127–3131. doi: 10.1098/rspb.2007.1251

[2] Wagner, D., & Nicklen, E. F. (2010). Ant nest location, soil nutrients and nutrient uptake by ant-associated plants: does extrafloral nectar attract ant nests and thereby enhance plant nutrition? Journal of Ecology, 98(3), 614–624. doi: 10.1111/j.1365-2745.2010.01640.x

[3] Silva, A. X., Jander, G., Samaniego, H., Ramsey, J. S., & Figueroa, C. C. (2012). Insecticide resistance mechanisms in the green peach aphid Myzus persicae (Hemiptera: Aphididae) I: A transcriptomic survey. PloS one, 7(6), e36366. https://doi.org/10.1371/journal.pone.0036366 

[4] Moran, N., & Jarvik, T. (2010). Lateral Transfer of Genes from Fungi Underlies Carotenoid Production in Aphids. Science, 328(5978), new series, 624-627. Retrieved March 15, 2021, from http://www.jstor.org/stable/40655838

[5] ISHIKAWA, A., & MIURA, T. (2013). Transduction of high-density signals across generations in aphid wing polyphenism. Physiological Entomology, 38(2), 150-156. doi:10.1111/phen.12022